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Kanai SM, Garcia CR, Augustus MR, Sharafeldeen SA, Brooks EP, Sucharov J, Lencer ES, Nichols JT, Clouthier DE. The Gq/11 family of Gα subunits is necessary and sufficient for lower jaw development. Development 2025; 152:dev204396. [PMID: 40171762 PMCID: PMC12045641 DOI: 10.1242/dev.204396] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2024] [Accepted: 03/18/2025] [Indexed: 04/04/2025]
Abstract
Vertebrate jaw development is coordinated by highly conserved ligand-receptor systems such as the peptide ligand Endothelin 1 (Edn1) and Endothelin receptor type A (Ednra), which are required for patterning of lower jaw structures. The Edn1/Ednra signaling pathway establishes the identity of lower jaw progenitor cells by regulating expression of numerous patterning genes, but the intracellular signaling mechanisms linking receptor activation to gene regulation remain poorly understood. As a first step towards elucidating this mechanism, we examined the function of the Gq/11 family of Gα subunits in zebrafish using pharmacological inhibition and genetic ablation of Gq/11 activity, and transgenic induction of a constitutively active Gq protein in edn1-/- embryos. Genetic loss of Gq/11 activity fully recapitulated the edn1-/- phenotype, with genes encoding G11 being most essential. Furthermore, inducing Gq activity in edn1-/- embryos not only restored Edn1/Ednra-dependent jaw structures and gene expression signatures but also caused homeosis of the upper jaw structure into a lower jaw-like structure. These results indicate that Gq/11 is necessary and sufficient to mediate the lower jaw patterning mechanism for Ednra in zebrafish.
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Affiliation(s)
- Stanley M. Kanai
- Department of Craniofacial Biology, School of Dental Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO 80108, USA
| | - Chloe R. Garcia
- Department of Craniofacial Biology, School of Dental Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO 80108, USA
| | - MaCalia R. Augustus
- Department of Craniofacial Biology, School of Dental Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO 80108, USA
| | - Shujan A. Sharafeldeen
- Department of Craniofacial Biology, School of Dental Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO 80108, USA
| | - Elliott P. Brooks
- Department of Craniofacial Biology, School of Dental Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO 80108, USA
| | - Juliana Sucharov
- Department of Craniofacial Biology, School of Dental Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO 80108, USA
| | - Ezra S. Lencer
- Department of Biology, Lafayette College, Easton, PA 18042, USA
| | - James T. Nichols
- Department of Craniofacial Biology, School of Dental Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO 80108, USA
| | - David E. Clouthier
- Department of Craniofacial Biology, School of Dental Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO 80108, USA
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2
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Kanai SM, Garcia CR, Augustus MR, Sharafeldeen SA, Brooks EP, Sucharov J, Lencer ES, Nichols JT, Clouthier DE. The Gq/11 family of Gα subunits is necessary and sufficient for lower jaw development. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.09.17.611698. [PMID: 39345358 PMCID: PMC11430119 DOI: 10.1101/2024.09.17.611698] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 10/01/2024]
Abstract
Vertebrate jaw development is coordinated by highly conserved ligand-receptor systems such as the peptide ligand Endothelin 1 (Edn1) and Endothelin receptor type A (Ednra), which are required for patterning of lower jaw structures. The Edn1/Ednra signaling pathway establishes the identity of lower jaw progenitor cells by regulating expression of numerous patterning genes, but the intracellular signaling mechanisms linking receptor activation to gene regulation remain poorly understood. As a first step towards elucidating this mechanism, we examined the function of the Gq/11 family of Gα subunits in zebrafish using pharmacological inhibition and genetic ablation of Gq/11 activity and transgenic induction of a constitutively active Gq protein in edn1 -/- embryos. Genetic loss of Gq/11 activity fully recapitulated the edn1 -/- phenotype, with genes encoding G11 being most essential. Furthermore, inducing Gq activity in edn1 -/- embryos not only restored Edn1/Ednra-dependent jaw structures and gene expression signatures but also caused homeosis of the upper jaw structure into a lower jaw-like structure. These results indicate that Gq/11 is necessary and sufficient to mediate the lower jaw patterning mechanism for Ednra in zebrafish.
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Affiliation(s)
- Stanley M. Kanai
- Department of Craniofacial Biology, School of Dental Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO USA
| | - Chloe R. Garcia
- Department of Craniofacial Biology, School of Dental Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO USA
| | - MaCalia R. Augustus
- Department of Craniofacial Biology, School of Dental Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO USA
| | - Shujan A. Sharafeldeen
- Department of Craniofacial Biology, School of Dental Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO USA
| | - Elliott P. Brooks
- Department of Craniofacial Biology, School of Dental Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO USA
| | - Juliana Sucharov
- Department of Craniofacial Biology, School of Dental Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO USA
| | - Ezra S. Lencer
- Department of Biology, Lafayette College, Easton, PA USA
| | - James T. Nichols
- Department of Craniofacial Biology, School of Dental Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO USA
| | - David E. Clouthier
- Department of Craniofacial Biology, School of Dental Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO USA
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3
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Jarysta A, Tadenev ALD, Day M, Krawchuk B, Low BE, Wiles MV, Tarchini B. Inhibitory G proteins play multiple roles to polarize sensory hair cell morphogenesis. eLife 2024; 12:RP88186. [PMID: 38651641 PMCID: PMC11037916 DOI: 10.7554/elife.88186] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/25/2024] Open
Abstract
Inhibitory G alpha (GNAI or Gαi) proteins are critical for the polarized morphogenesis of sensory hair cells and for hearing. The extent and nature of their actual contributions remains unclear, however, as previous studies did not investigate all GNAI proteins and included non-physiological approaches. Pertussis toxin can downregulate functionally redundant GNAI1, GNAI2, GNAI3, and GNAO proteins, but may also induce unrelated defects. Here, we directly and systematically determine the role(s) of each individual GNAI protein in mouse auditory hair cells. GNAI2 and GNAI3 are similarly polarized at the hair cell apex with their binding partner G protein signaling modulator 2 (GPSM2), whereas GNAI1 and GNAO are not detected. In Gnai3 mutants, GNAI2 progressively fails to fully occupy the sub-cellular compartments where GNAI3 is missing. In contrast, GNAI3 can fully compensate for the loss of GNAI2 and is essential for hair bundle morphogenesis and auditory function. Simultaneous inactivation of Gnai2 and Gnai3 recapitulates for the first time two distinct types of defects only observed so far with pertussis toxin: (1) a delay or failure of the basal body to migrate off-center in prospective hair cells, and (2) a reversal in the orientation of some hair cell types. We conclude that GNAI proteins are critical for hair cells to break planar symmetry and to orient properly before GNAI2/3 regulate hair bundle morphogenesis with GPSM2.
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Affiliation(s)
| | | | - Matthew Day
- The Jackson LaboratoryBar HarborUnited States
| | | | | | | | - Basile Tarchini
- The Jackson LaboratoryBar HarborUnited States
- Tufts University School of MedicineBostonUnited States
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4
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Schröper T, Mehrkens D, Leiss V, Tellkamp F, Engelhardt S, Herzig S, Birnbaumer L, Nürnberg B, Matthes J. Protective effects of Gα i3 deficiency in a murine heart-failure model of β 1-adrenoceptor overexpression. NAUNYN-SCHMIEDEBERG'S ARCHIVES OF PHARMACOLOGY 2024; 397:2401-2420. [PMID: 37843590 PMCID: PMC10933181 DOI: 10.1007/s00210-023-02751-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/08/2023] [Accepted: 09/26/2023] [Indexed: 10/17/2023]
Abstract
We have shown that in murine cardiomyopathy caused by overexpression of the β1-adrenoceptor, Gαi2-deficiency is detrimental. Given the growing evidence for isoform-specific Gαi-functions, we now examined the consequences of Gαi3 deficiency in the same heart-failure model. Mice overexpressing cardiac β1-adrenoceptors with (β1-tg) or without Gαi3-expression (β1-tg/Gαi3-/-) were compared to C57BL/6 wildtypes and global Gαi3-knockouts (Gαi3-/-). The life span of β1-tg mice was significantly shortened but improved when Gαi3 was lacking (95% CI: 592-655 vs. 644-747 days). At 300 days of age, left-ventricular function and survival rate were similar in all groups. At 550 days of age, β1-tg but not β1-tg/Gαi3-/- mice displayed impaired ejection fraction (35 ± 18% vs. 52 ± 16%) compared to wildtype (59 ± 4%) and Gαi3-/- mice (60 ± 5%). Diastolic dysfunction of β1-tg mice was prevented by Gαi3 deficiency, too. The increase of ANP mRNA levels and ventricular fibrosis observed in β1-tg hearts was significantly attenuated in β1-tg/Gαi3-/- mice. Transcript levels of phospholamban, ryanodine receptor 2, and cardiac troponin I were similar in all groups. However, Western blots and phospho-proteomic analyses showed that in β1-tg, but not β1-tg/Gαi3-/- ventricles, phospholamban protein was reduced while its phosphorylation increased. Here, we show that in mice overexpressing the cardiac β1-adrenoceptor, Gαi3 deficiency slows or even prevents cardiomyopathy and increases shortened life span. Previously, we found Gαi2 deficiency to aggravate cardiac dysfunction and mortality in the same heart-failure model. Our findings indicate isoform-specific interventions into Gi-dependent signaling to be promising cardio-protective strategies.
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Affiliation(s)
- Tobias Schröper
- Center of Pharmacology, Department II, University of Cologne and University Hospital Cologne, Cologne, Germany
- Department of Internal Medicine III, University Hospital of Cologne, Cologne, Germany and Centre for Molecular Medicine Cologne, University of Cologne, Cologne, Germany
| | - Dennis Mehrkens
- Department of Internal Medicine III, University Hospital of Cologne, Cologne, Germany and Centre for Molecular Medicine Cologne, University of Cologne, Cologne, Germany
- Centre for Molecular Medicine Cologne, CMMC, University of Cologne, Cologne, Germany
| | - Veronika Leiss
- Department of Pharmacology, Experimental Therapy and Toxicology, Institute for Experimental and Clinical Pharmacology and Pharmacogenomics, and Interfaculty Centre for Pharmacogenomics and Drug Research, Eberhard Karls Universität, Tübingen, Germany
| | - Frederik Tellkamp
- CECAD Research Centre Institute for Genetics, University of Cologne, Cologne, Germany
| | - Stefan Engelhardt
- Institute of Pharmacology and Toxicology, Technische Universität München, Munich, Germany
| | - Stefan Herzig
- Center of Pharmacology, Department II, University of Cologne and University Hospital Cologne, Cologne, Germany
- TH Köln-University of Applied Sciences, Cologne, Germany
| | - Lutz Birnbaumer
- Laboratory of Signal Transduction, National Institute of Environmental Health Sciences, Research Triangle Park, Durham, North Carolina, USA
- Institute of Biomedical Research, School of Medical Sciences, Catholic University of Buenos Aires, Buenos Aires, Argentina
| | - Bernd Nürnberg
- Department of Pharmacology, Experimental Therapy and Toxicology, Institute for Experimental and Clinical Pharmacology and Pharmacogenomics, and Interfaculty Centre for Pharmacogenomics and Drug Research, Eberhard Karls Universität, Tübingen, Germany
| | - Jan Matthes
- Center of Pharmacology, Department II, University of Cologne and University Hospital Cologne, Cologne, Germany.
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5
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Nürnberg B, Beer-Hammer S, Reisinger E, Leiss V. Non-canonical G protein signaling. Pharmacol Ther 2024; 255:108589. [PMID: 38295906 DOI: 10.1016/j.pharmthera.2024.108589] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Revised: 12/18/2023] [Accepted: 01/08/2024] [Indexed: 02/17/2024]
Abstract
The original paradigm of classical - also referred to as canonical - cellular signal transduction of heterotrimeric G proteins (G protein) is defined by a hierarchical, orthograde interaction of three players: the agonist-activated G protein-coupled receptor (GPCR), which activates the transducing G protein, that in turn regulates its intracellular effectors. This receptor-transducer-effector concept was extended by the identification of regulators and adapters such as the regulators of G protein signaling (RGS), receptor kinases like βARK, or GPCR-interacting arrestin adapters that are integrated into this canonical signaling process at different levels to enable fine-tuning. Finally, the identification of atypical signaling mechanisms of classical regulators, together with the discovery of novel modulators, added a new and fascinating dimension to the cellular G protein signal transduction. This heterogeneous group of accessory G protein modulators was coined "activators of G protein signaling" (AGS) proteins and plays distinct roles in canonical and non-canonical G protein signaling pathways. AGS proteins contribute to the control of essential cellular functions such as cell development and division, intracellular transport processes, secretion, autophagy or cell movements. As such, they are involved in numerous biological processes that are crucial for diseases, like diabetes mellitus, cancer, and stroke, which represent major health burdens. Although the identification of a large number of non-canonical G protein signaling pathways has broadened the spectrum of this cellular communication system, their underlying mechanisms, functions, and biological effects are poorly understood. In this review, we highlight and discuss atypical G protein-dependent signaling mechanisms with a focus on inhibitory G proteins (Gi) involved in canonical and non-canonical signal transduction, review recent developments and open questions, address the potential of new approaches for targeted pharmacological interventions.
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Affiliation(s)
- Bernd Nürnberg
- Department of Pharmacology, Experimental Therapy and Toxicology, Institute of Experimental and Clinical Pharmacology and Pharmacogenomics, and ICePhA Mouse Clinic, University of Tübingen, Wilhelmstraße 56, D-72074 Tübingen, Germany.
| | - Sandra Beer-Hammer
- Department of Pharmacology, Experimental Therapy and Toxicology, Institute of Experimental and Clinical Pharmacology and Pharmacogenomics, and ICePhA Mouse Clinic, University of Tübingen, Wilhelmstraße 56, D-72074 Tübingen, Germany
| | - Ellen Reisinger
- Gene Therapy for Hearing Impairment Group, Department of Otolaryngology - Head & Neck Surgery, University of Tübingen Medical Center, Elfriede-Aulhorn-Straße 5, D-72076 Tübingen, Germany
| | - Veronika Leiss
- Department of Pharmacology, Experimental Therapy and Toxicology, Institute of Experimental and Clinical Pharmacology and Pharmacogenomics, and ICePhA Mouse Clinic, University of Tübingen, Wilhelmstraße 56, D-72074 Tübingen, Germany
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6
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Jarysta A, Tadenev ALD, Day M, Krawchuk B, Low BE, Wiles MV, Tarchini B. Inhibitory G proteins play multiple roles to polarize sensory hair cell morphogenesis. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.05.25.542257. [PMID: 37292807 PMCID: PMC10245865 DOI: 10.1101/2023.05.25.542257] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Inhibitory G alpha (GNAI or Gαi) proteins are critical for the polarized morphogenesis of sensory hair cells and for hearing. The extent and nature of their actual contributions remains unclear, however, as previous studies did not investigate all GNAI proteins and included non-physiological approaches. Pertussis toxin can downregulate functionally redundant GNAI1, GNAI2, GNAI3 and GNAO proteins, but may also induce unrelated defects. Here we directly and systematically determine the role(s) of each individual GNAI protein in mouse auditory hair cells. GNAI2 and GNAI3 are similarly polarized at the hair cell apex with their binding partner GPSM2, whereas GNAI1 and GNAO are not detected. In Gnai3 mutants, GNAI2 progressively fails to fully occupy the subcellular compartments where GNAI3 is missing. In contrast, GNAI3 can fully compensate for the loss of GNAI2 and is essential for hair bundle morphogenesis and auditory function. Simultaneous inactivation of Gnai2 and Gnai3 recapitulates for the first time two distinct types of defects only observed so far with pertussis toxin: 1) a delay or failure of the basal body to migrate off-center in prospective hair cells, and 2) a reversal in the orientation of some hair cell types. We conclude that GNAI proteins are critical for hair cells to break planar symmetry and to orient properly before GNAI2/3 regulate hair bundle morphogenesis with GPSM2.
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7
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Haque MA, Alam MZ, Iqbal A, Lee YM, Dang CG, Kim JJ. Genome-Wide Association Studies for Body Conformation Traits in Korean Holstein Population. Animals (Basel) 2023; 13:2964. [PMID: 37760364 PMCID: PMC10526087 DOI: 10.3390/ani13182964] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2023] [Revised: 09/15/2023] [Accepted: 09/18/2023] [Indexed: 09/29/2023] Open
Abstract
The objective of this study was to identify quantitative trait loci (QTL) and nearby candidate genes that influence body conformation traits. Phenotypic data for 24 body conformation traits were collected from a population of 2329 Korean Holstein cattle, and all animals were genotyped using the 50 K Illumina bovine SNP chip. A total of 24 genome-wide significant SNPs associated with 24 body conformation traits were identified by genome-wide association analysis. The selection of the most promising candidate genes was based on gene ontology (GO) terms and the previously identified functions that influence various body conformation traits as determined in our study. These genes include KCNA1, RYBP, PTH1R, TMIE, and GNAI3 for body traits; ANGPT1 for rump traits; MALRD1, INHBA, and HOXA13 for feet and leg traits; and CDK1, RHOBTB1, and SLC17A1 for udder traits, respectively. These findings contribute to our understanding of the genetic basis of body conformation traits in this population and pave the way for future breeding strategies aimed at enhancing desirable traits in dairy cattle.
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Affiliation(s)
- Md Azizul Haque
- Department of Biotechnology, Yeungnam University, Gyeongsan 38541, Gyeongbuk, Republic of Korea; (M.A.H.); (M.Z.A.); (A.I.); (Y.-M.L.)
| | - Mohammad Zahangir Alam
- Department of Biotechnology, Yeungnam University, Gyeongsan 38541, Gyeongbuk, Republic of Korea; (M.A.H.); (M.Z.A.); (A.I.); (Y.-M.L.)
| | - Asif Iqbal
- Department of Biotechnology, Yeungnam University, Gyeongsan 38541, Gyeongbuk, Republic of Korea; (M.A.H.); (M.Z.A.); (A.I.); (Y.-M.L.)
| | - Yun-Mi Lee
- Department of Biotechnology, Yeungnam University, Gyeongsan 38541, Gyeongbuk, Republic of Korea; (M.A.H.); (M.Z.A.); (A.I.); (Y.-M.L.)
| | - Chang-Gwon Dang
- Animal Breeding and Genetics Division, National Institute of Animal Science, Cheonan 31000, Chungcheongnam-do, Republic of Korea
| | - Jong-Joo Kim
- Department of Biotechnology, Yeungnam University, Gyeongsan 38541, Gyeongbuk, Republic of Korea; (M.A.H.); (M.Z.A.); (A.I.); (Y.-M.L.)
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8
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Villaseca S, Romero G, Ruiz MJ, Pérez C, Leal JI, Tovar LM, Torrejón M. Gαi protein subunit: A step toward understanding its non-canonical mechanisms. Front Cell Dev Biol 2022; 10:941870. [PMID: 36092739 PMCID: PMC9449497 DOI: 10.3389/fcell.2022.941870] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Accepted: 08/01/2022] [Indexed: 11/13/2022] Open
Abstract
The heterotrimeric G protein family plays essential roles during a varied array of cellular events; thus, its deregulation can seriously alter signaling events and the overall state of the cell. Heterotrimeric G-proteins have three subunits (α, β, γ) and are subdivided into four families, Gαi, Gα12/13, Gαq, and Gαs. These proteins cycle between an inactive Gα-GDP state and active Gα-GTP state, triggered canonically by the G-protein coupled receptor (GPCR) and by other accessory proteins receptors independent also known as AGS (Activators of G-protein Signaling). In this review, we summarize research data specific for the Gαi family. This family has the largest number of individual members, including Gαi1, Gαi2, Gαi3, Gαo, Gαt, Gαg, and Gαz, and constitutes the majority of G proteins α subunits expressed in a tissue or cell. Gαi was initially described by its inhibitory function on adenylyl cyclase activity, decreasing cAMP levels. Interestingly, today Gi family G-protein have been reported to be importantly involved in the immune system function. Here, we discuss the impact of Gαi on non-canonical effector proteins, such as c-Src, ERK1/2, phospholipase-C (PLC), and proteins from the Rho GTPase family members, all of them essential signaling pathways regulating a wide range of physiological processes.
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9
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Vegas N, Demir Z, Gordon CT, Breton S, Romanelli Tavares V, Moisset H, Zechi-Ceide R, Kokitsu-Nakata NM, Kido Y, Marlin S, Gherbi Halem S, Meerschaut I, Callewaert B, Chung B, Revencu N, Lehalle D, Petit F, Propst EJ, Papsin BC, Phillips JH, Jakobsen L, Le Tanno P, Thévenon J, McGaughran J, Gerkes EH, Leoni C, Kroisel P, Yang Tan T, Henderson A, Terhal P, Basel-Salmon L, Alkindy A, White SM, Passos Bueno MR, Pingault V, De Pontual L, Amiel J. Further delineation of Auriculocondylar syndrome based on 14 novel cases and reassessment of 25 published cases. Hum Mutat 2022; 43:582-594. [PMID: 35170830 DOI: 10.1002/humu.24349] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Revised: 02/08/2022] [Accepted: 02/11/2022] [Indexed: 11/08/2022]
Abstract
Auriculocondylar syndrome (ACS) is a rare craniofacial disorder characterized by mandibular hypoplasia and an auricular defect at the junction between the lobe and helix, known as a "Question Mark Ear" (QME). Several additional features, originating from the first and second branchial arches and other tissues, have also been reported. ACS is genetically heterogeneous with autosomal dominant and recessive modes of inheritance. The mutations identified to date are presumed to dysregulate the endothelin 1 signalling pathway. Here we describe 14 novel cases and reassess 25 published cases of ACS through a questionnaire for systematic data collection. All patients harbour mutation(s) in PLCB4, GNAI3 or EDN1. This series of patients contributes to the characterization of additional features occasionally associated with ACS such as respiratory, costal, neurodevelopmental and genital anomalies, and provides management and monitoring recommendations. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Nancy Vegas
- Laboratory of Embryology and Genetics of Malformations, Institut National de la Santé et de la Recherche Médicale (INSERM) UMR 1163, Université de Paris, Institut Imagine, Paris, France
| | - Zeynep Demir
- Laboratory of Embryology and Genetics of Malformations, Institut National de la Santé et de la Recherche Médicale (INSERM) UMR 1163, Université de Paris, Institut Imagine, Paris, France.,Unité d'hépatologie pédiatrie et transplantation, Hôpital Necker-Enfants Malades, AP-HP, Paris, France
| | - Christopher T Gordon
- Laboratory of Embryology and Genetics of Malformations, Institut National de la Santé et de la Recherche Médicale (INSERM) UMR 1163, Université de Paris, Institut Imagine, Paris, France
| | - Sylvain Breton
- Service d'imagerie pédiatrie, Hôpital Necker-Enfants Malades, AP-HP, Paris, France
| | - Vanessa Romanelli Tavares
- Centro de Pesquisas do Genoma Humano e Celulas Tronco, Departamento de Genetica e Biología Evolutiva, Instituto de Biociencias, Universidade de Sao Paulo, Sao Paulo, Brazil
| | - Hugo Moisset
- Laboratory of Embryology and Genetics of Malformations, Institut National de la Santé et de la Recherche Médicale (INSERM) UMR 1163, Université de Paris, Institut Imagine, Paris, France
| | - Roseli Zechi-Ceide
- Department of Clinical Genetics, Hospital for Rehabilitation of Craniofacial Anomalies, University of Sao Paulo, Bauru, Brazil
| | - Nancy M Kokitsu-Nakata
- Department of Clinical Genetics, Hospital for Rehabilitation of Craniofacial Anomalies, University of Sao Paulo, Bauru, Brazil
| | - Yasuhiro Kido
- Department of Pediatrics, Dokkyo Medical University Koshigaya Hospital, Saitama, Japan
| | - Sandrine Marlin
- Laboratory of Embryology and Genetics of Malformations, Institut National de la Santé et de la Recherche Médicale (INSERM) UMR 1163, Université de Paris, Institut Imagine, Paris, France.,Reference center for genetic hearing loss, Fédération de Génétique et de Médecine Génomique, Hôpital Necker, APHP.CUP, Paris, France
| | - Souad Gherbi Halem
- Reference center for genetic hearing loss, Fédération de Génétique et de Médecine Génomique, Hôpital Necker, APHP.CUP, Paris, France
| | - Ilse Meerschaut
- Center for Medical Genetics, Ghent University Hospital, and Department of Biomolecular Medicine, Ghent University, Belgium
| | - Bert Callewaert
- Center for Medical Genetics, Ghent University Hospital, and Department of Biomolecular Medicine, Ghent University, Belgium
| | - Brian Chung
- Department of Paediatrics and Adolescent Medicine, The University of Hong Kong, Hong Kong
| | - Nicole Revencu
- Center for Human Genetics, Cliniques universitaires Saint Luc, Université catholique de Louvain, Brussels, Belgium
| | - Daphné Lehalle
- Centre de génétique- centre de référence des maladies rares, anomalies du développement et syndrome malformatifs, Centre Hospitalo-Universitaire de Dijon, Bourgogne, France.,UF de Génétique Médicale, Département de Génétique, Groupe Hospitalier Pitié-Salpêtrière, APHP Sorbonne Université, Paris, France
| | - Florence Petit
- CHU Lille, clinique de Génétique Guy Fontaine, F-59000, Lille, France
| | - Evan J Propst
- Department of Otolaryngology-Head and Neck Surgery, The Hospital for Sick Children, University of Toronto, Canada
| | - Blake C Papsin
- Department of Otolaryngology-Head and Neck Surgery, The Hospital for Sick Children, University of Toronto, Canada
| | - John H Phillips
- Department of Otolaryngology-Head and Neck Surgery, The Hospital for Sick Children, University of Toronto, Canada
| | - Linda Jakobsen
- Department of Plastic Surgery, Copenhagen University Hospital, Herlev, Denmark
| | - Pauline Le Tanno
- Service de Génétique et Université Grenoble-Alpes, Grenoble, France
| | - Julien Thévenon
- Service de Génétique et Université Grenoble-Alpes, Grenoble, France
| | - Julie McGaughran
- Genetic Health Queensland, Royal Brisbane and Women's Hospital, Herston and the University of Queensland, St Lucia, Brisbane, Australia
| | - Erica H Gerkes
- Department of Genetics, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands
| | - Chiara Leoni
- Center for Rare Diseases and Birth Defects, Department of Woman and Child Health and Public Health, Fondazione Policlinico A. Gemelli, IRCCS, Italy
| | - Peter Kroisel
- Institute of Human Genetics, Medical University of Graz, Graz, Austria
| | - Tiong Yang Tan
- Victorian Clinical Genetics Services, Murdoch Children's Research Institute, Royal Children's Hospital, and Department of Paediatrics, University of Melbourne, Melbourne, Victoria, Australia
| | - Alex Henderson
- Northern Genetics Service, Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle Upon Tyne, UK
| | - Paulien Terhal
- Department of Medical Genetics, University Medical Centre Utrecht, Utrecht, The Netherlands
| | - Lina Basel-Salmon
- Pediatric Genetics, Schneider Children's Medical Center of Israel and Raphael Recanati Genetics Institute, Rabin Medical Center, Beilinson Campus, Petah Tikva, Israel.,Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.,Felsenstein Medical Research Center, Rabin Medical Center, Petah Tikva, Israel
| | - Adila Alkindy
- Department of Genetics, Sultan Qaboos University Hospital, Muscat, Oman
| | - Susan M White
- Victorian Clinical Genetics Services, Murdoch Children's Research Institute, Royal Children's Hospital, and Department of Paediatrics, University of Melbourne, Melbourne, Victoria, Australia
| | - Maria Rita Passos Bueno
- Centro de Pesquisas do Genoma Humano e Celulas Tronco, Departamento de Genetica e Biología Evolutiva, Instituto de Biociencias, Universidade de Sao Paulo, Sao Paulo, Brazil
| | - Véronique Pingault
- Laboratory of Embryology and Genetics of Malformations, Institut National de la Santé et de la Recherche Médicale (INSERM) UMR 1163, Université de Paris, Institut Imagine, Paris, France.,Fédération de Génétique et de Médecine Génomique, Hôpital Necker, APHP.CUP, Paris, France
| | - Loïc De Pontual
- Laboratory of Embryology and Genetics of Malformations, Institut National de la Santé et de la Recherche Médicale (INSERM) UMR 1163, Université de Paris, Institut Imagine, Paris, France.,Service de pédiatrie, Hôpital Jean Verdier, Bondy, France
| | - Jeanne Amiel
- Laboratory of Embryology and Genetics of Malformations, Institut National de la Santé et de la Recherche Médicale (INSERM) UMR 1163, Université de Paris, Institut Imagine, Paris, France.,Fédération de Génétique et de Médecine Génomique, Hôpital Necker, APHP.CUP, Paris, France
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10
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Zhang Z, Ji Z, He J, Lu Y, Tian W, Zheng C, Chen H, Zhang Q, Yang F, Zhang M, Yin Y, Jiang R, Chu WM, Zhang W, Sun B. Guanine Nucleotide-Binding Protein G(i) Subunit Alpha 2 Exacerbates NASH Progression by Regulating Peroxiredoxin 1-Related Inflammation and Lipophagy. Hepatology 2021; 74:3110-3126. [PMID: 34322898 DOI: 10.1002/hep.32078] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Revised: 06/03/2021] [Accepted: 07/15/2021] [Indexed: 12/27/2022]
Abstract
BACKGROUND AND AIMS NASH is an advanced stage of liver disease accompanied by lipid accumulation, inflammation, and liver fibrosis. Guanine nucleotide-binding protein G(i) subunit alpha-2 (GNAI2) is a member of the "inhibitory" class of α-subunits, and recent studies showed that Gnai2 deficiency is known to cause reduced weight in mice. However, the role of GNAI2 in hepatocytes, particularly in the context of liver inflammation and lipid metabolism, remains to be elucidated. Herein, we aim to ascertain the function of GNAI2 in hepatocytes and its impact on the development of NASH. APPROACH AND RESULTS Human liver tissues were obtained from NASH patients and healthy persons to evaluate the expression and clinical relevance of GNAI2. In addition, hepatocyte-specific Gnai2-deficient mice (Gnai2hep-/- ) were fed either a Western diet supplemented with fructose in drinking water (WDF) for 16 weeks or a methionine/choline-deficient diet (MCD) for 6 weeks to investigate the regulatory role and underlying mechanism of Gnai2 in NASH. GNAI2 was significantly up-regulated in liver tissues of patients with NASH. Following feeding with WDF or MCD diets, livers from Gnai2hep-/- mice had reduced steatohepatitis with suppression of markers of inflammation and an increase in lipophagy compared to Gnai2flox/flox mice. Toll-like receptor 4 signals through nuclear factor kappa B to trigger p65-dependent transcription of Gnai2. Intriguingly, immunoprecipitation, immunofluorescence, and mass spectrometry identified peroxiredoxin 1 (PRDX1) as a binding partner of GNAI2. Moreover, the function of PRDX1 in the suppression of TNF receptor-associated factor 6 ubiquitin-ligase activity and glycerophosphodiester phosphodiesterase domain-containing 5-related phosphatidylcholine metabolism was inhibited by GNAI2. Suppression of GNAI2 combined with overexpression of PRDX1 reversed the development of steatosis and fibrosis in vivo. CONCLUSIONS GNAI2 is a major regulator that leads to the development of NASH. Thus, inhibition of GNAI2 could be an effective therapeutic target for the treatment of NASH.
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Affiliation(s)
- Zechuan Zhang
- Department of Hepatobiliary Surgery, The Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, China.,Department of Hepatobiliary Surgery, Nanjing Drum Tower Hospital Clinical College of Nanjing Medical University, Nanjing, China
| | - Zetao Ji
- Department of Hepatobiliary Surgery, The Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, China
| | - Jianbo He
- Department of Hepatobiliary Surgery, The Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, China
| | - Yijun Lu
- Department of Hepatobiliary Surgery, The Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, China
| | - Wenfang Tian
- Department of Hepatobiliary Surgery, The Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, China
| | - Chang Zheng
- Medical School of Nanjing University, Nanjing, China
| | - Huihui Chen
- Department of Hepatobiliary Surgery, The Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, China
| | - Quan Zhang
- Medical School of Nanjing University, Nanjing, China
| | - Fei Yang
- Department of Hepatobiliary Surgery, The Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, China
| | - Minglu Zhang
- Department of Hepatobiliary Surgery, The Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, China
| | - Yin Yin
- Department of Hepatobiliary Surgery, The Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, China.,Department of Hepatobiliary Surgery, Nanjing Drum Tower Hospital Clinical College of Nanjing Medical University, Nanjing, China
| | - Runqiu Jiang
- Department of Hepatobiliary Surgery, The Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, China.,Department of Hepatobiliary Surgery, Nanjing Drum Tower Hospital Clinical College of Nanjing Medical University, Nanjing, China.,Medical School of Nanjing University, Nanjing, China
| | - Wen-Ming Chu
- Manoa Institute for Life Science and Cancer, Honolulu, HI, USA
| | - Wenjie Zhang
- Department of Hepatobiliary Surgery, The Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, China.,Department of Hepatobiliary Surgery, Nanjing Drum Tower Hospital Clinical College of Nanjing Medical University, Nanjing, China
| | - Beicheng Sun
- Department of Hepatobiliary Surgery, The Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, China.,Department of Hepatobiliary Surgery, Nanjing Drum Tower Hospital Clinical College of Nanjing Medical University, Nanjing, China
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11
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Leiss V, Reisinger E, Speidel A, Beer-Hammer S, Nürnberg B. Analyses of Gnai3-iresGFP reporter mice reveal unknown Gα i3 expression sites. Sci Rep 2021; 11:14271. [PMID: 34253772 PMCID: PMC8275620 DOI: 10.1038/s41598-021-93591-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Accepted: 06/21/2021] [Indexed: 12/01/2022] Open
Abstract
Inhibitory G proteins (Gi proteins) are highly homologous but play distinct biological roles. However, their isoform-specific detection remains challenging. To facilitate the analysis of Gαi3 expression, we generated a Gnai3- iresGFP reporter mouse line. An internal ribosomal entry site (IRES) was inserted behind the stop-codon of the Gnai3 gene to initiate simultaneous translation of the GFP cDNA together with Gαi3. The expression of GFP was confirmed in spleen and thymus tissue by immunoblot analysis. Importantly, the GFP knock-in (ki) did not alter Gαi3 expression levels in all organs tested including spleen and thymus compared to wild-type littermates. Flow cytometry of thymocytes, splenic and blood cell suspensions revealed significantly higher GFP fluorescence intensities in homozygous ki/ki animals compared to heterozygous mice (+/ki). Using cell-type specific surface markers GFP fluorescence was assigned to B cells, T cells, macrophages and granulocytes from both splenic and blood cells and additionally blood-derived platelets. Moreover, immunofluorescent staining of the inner ear from knock-in mice unraveled GFP expression in sensory and non-sensory cell types, with highest levels in Deiter's cells and in the first row of Hensen's cells in the organ of Corti, indicating a novel site for Gαi3 expression. In summary, the Gnai3- iresGFP reporter mouse represents an ideal tool for precise analyses of Gαi3 expression patterns and sites.
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Affiliation(s)
- Veronika Leiss
- Department of Pharmacology, Experimental Therapy and Toxicology, Institute of Experimental and Clinical Pharmacology and Pharmacogenomics, and ICePhA Mouse Clinic, University of Tübingen, Wilhelmstraße 56, 72074, Tübingen, Germany
| | - Ellen Reisinger
- Department of Otolaryngology-Head and Neck Surgery, Gene Therapy for Hearing Impairment Group, University of Tübingen, Medical Center, Elfriede-Aulhorn-Straße 5, 72076, Tübingen, Germany
| | - Annika Speidel
- Department of Pharmacology, Experimental Therapy and Toxicology, Institute of Experimental and Clinical Pharmacology and Pharmacogenomics, and ICePhA Mouse Clinic, University of Tübingen, Wilhelmstraße 56, 72074, Tübingen, Germany
| | - Sandra Beer-Hammer
- Department of Pharmacology, Experimental Therapy and Toxicology, Institute of Experimental and Clinical Pharmacology and Pharmacogenomics, and ICePhA Mouse Clinic, University of Tübingen, Wilhelmstraße 56, 72074, Tübingen, Germany.
| | - Bernd Nürnberg
- Department of Pharmacology, Experimental Therapy and Toxicology, Institute of Experimental and Clinical Pharmacology and Pharmacogenomics, and ICePhA Mouse Clinic, University of Tübingen, Wilhelmstraße 56, 72074, Tübingen, Germany
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12
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Functional approaches to the study of G-protein-coupled receptors in postmortem brain tissue: [ 35S]GTPγS binding assays combined with immunoprecipitation. Pharmacol Rep 2021; 73:1079-1095. [PMID: 33876404 DOI: 10.1007/s43440-021-00253-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Revised: 03/16/2021] [Accepted: 03/19/2021] [Indexed: 10/21/2022]
Abstract
G-protein-coupled receptors (GPCRs) have an enormous biochemical importance as they bind to diverse extracellular ligands and regulate a variety of physiological and pathological responses. G-protein activation measures the functional consequence of receptor occupancy at one of the earliest receptor-mediated events. Receptor coupling to G-proteins promotes the GDP/GTP exchange on Gα subunits. Thus, modulation of the binding of the poorly hydrolysable GTP analog [35S]GTPγS to the Gα-protein subunit can be used as a functional approach to quantify GPCR interaction with agonist, antagonist or inverse agonist drugs. In order to determine receptor-mediated selective activation of the different Gα-proteins, [35S]GTPγS binding assays combined with immunodetection by specific antibodies have been developed and applied to physiological and pathological brain conditions. Currently, immunoprecipitation with magnetic beads and scintillation proximity assays are the most habitual techniques for this purpose. The present review summarizes the different procedures, advantages and limitations of the [35S]GTPγS binding assays combined with selective Gα-protein sequestration methods. Experience of functional coupling of several GPCRs to different Gα-proteins and recommendations for optimal performance in brain membranes are described. One of the biggest opportunities opened by these techniques is that they enable evaluation of biased agonism in the native tissue, which results in high interest in drug discovery. The available results derived from application of these functional methodologies to study GPCR dysfunctions in neuro-psychiatric disorders are also described. In conclusion, [35S]GTPγS binding combined with antibody-mediated immunodetection represents an useful method to separately evaluate the functional activity of drugs acting on GPCRs over each Gα-protein subtype.
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13
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Leiss V, Schönsiegel A, Gnad T, Kerner J, Kaur J, Sartorius T, Machann J, Schick F, Birnbaumer L, Häring HU, Pfeifer A, Nürnberg B. Lack of Gα i2 proteins in adipocytes attenuates diet-induced obesity. Mol Metab 2020; 40:101029. [PMID: 32480042 PMCID: PMC7306590 DOI: 10.1016/j.molmet.2020.101029] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Revised: 05/26/2020] [Accepted: 05/26/2020] [Indexed: 12/20/2022] Open
Abstract
OBJECTIVES Typically, obesity results from an inappropriate balance between energy uptake from nutrient consumption and burning of calories, which leads to a pathological increase in fat mass. Obesity is a major cause of insulin resistance and diabetes. Inhibitory G proteins (Gαi) form a subfamily that is involved in the regulation of adipose tissue function. Among the three Gαi members, i.e. Gαi1, Gαi2, Gαi3, the Gαi2, protein is predominantly expressed in adipose tissue. However, the functions of the Gαi2 isoform in adipose tissue and its impact on the development of obesity are poorly understood. METHODS By using AdipoqCreERT2 mice, we generated adipocyte-specific Gnai2-deficient mice to study Gαi2 function, specifically in white and brown adipocytes. These mice were fed either a control diet (CD) or a high fat diet (HFD). Mice were examined for obesity development, insulin resistance and glucose intolerance. We examined adipocyte morphology and the development of inflammation in the white adipose tissue. Finally, intracellular cAMP levels as an indicator of Gαi signaling and glycerol release as an indicator of lipolysis rates were measured to verify the impact of Gαi2 on the signaling pathway in brown and white adipocytes. RESULTS An adipocyte-specific deficiency of Gαi2 significantly reduced diet-induced obesity, leading to decreased fat masses, smaller adipocytes and decreased inflammation in the white adipose tissue relative to littermate controls. Concurrently, oxygen consumption of brown adipocytes and in vivo measured energy expenditure were significantly enhanced. In addition, glucose tolerance and insulin sensitivity of HFD-fed adipocyte-specific Gnai2-deficient mice were improved compared to the respective controls. In the absence of Gαi2, adrenergic stimulation of intracellular adipocyte cAMP levels was increased, which correlated with increased lipolysis and energy expenditure. CONCLUSION We conclude that adipocyte Gαi2 is a major regulator of adipocyte lipid content in diet-induced obesity by inhibiting adipocyte lipolysis in a cAMP-dependent manner resulting in increased energy expenditure.
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MESH Headings
- Adipocytes, Brown/metabolism
- Adipocytes, White/metabolism
- Adipose Tissue/metabolism
- Adipose Tissue/physiology
- Adipose Tissue, Brown/metabolism
- Adipose Tissue, White/metabolism
- Animals
- Diet, High-Fat
- Energy Metabolism
- GTP-Binding Protein alpha Subunit, Gi2/metabolism
- GTP-Binding Protein alpha Subunit, Gi2/physiology
- GTP-Binding Protein alpha Subunits, Gi-Go/metabolism
- GTP-Binding Protein alpha Subunits, Gi-Go/physiology
- Glucose/metabolism
- Glucose Intolerance/metabolism
- Insulin/metabolism
- Insulin Resistance/physiology
- Lipolysis
- Male
- Mice
- Mice, Inbred C57BL
- Obesity/genetics
- Obesity/metabolism
- Oxygen Consumption
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Affiliation(s)
- Veronika Leiss
- Department of Pharmacology, Experimental Therapy and Toxicology and Interfaculty Center of Pharmacoge-nomics and Drug Research, University of Tübingen, 72074, Tübingen, Germany
| | - Annika Schönsiegel
- Department of Pharmacology, Experimental Therapy and Toxicology and Interfaculty Center of Pharmacoge-nomics and Drug Research, University of Tübingen, 72074, Tübingen, Germany
| | - Thorsten Gnad
- Institute of Pharmacology and Toxicology, University of Bonn, 53127, Bonn, Germany
| | - Johannes Kerner
- Department of Pharmacology, Experimental Therapy and Toxicology and Interfaculty Center of Pharmacoge-nomics and Drug Research, University of Tübingen, 72074, Tübingen, Germany
| | - Jyotsna Kaur
- Department of Pharmacology, Experimental Therapy and Toxicology and Interfaculty Center of Pharmacoge-nomics and Drug Research, University of Tübingen, 72074, Tübingen, Germany
| | - Tina Sartorius
- Department of Internal Medicine, Division of Endocrinology, Diabetology, Vascular Disease, Nephrology and Clinical Chemistry, University of Tuebingen, Tuebingen, Germany; German Center for Diabetes Research (DZD), Neuherberg, Germany; Institute for Diabetes Research and Metabolic Diseases of the Helmholtz Center Munich at the University of Tuebingen (IDM), Tuebingen, Germany
| | - Jürgen Machann
- German Center for Diabetes Research (DZD), Neuherberg, Germany; Institute for Diabetes Research and Metabolic Diseases of the Helmholtz Center Munich at the University of Tuebingen (IDM), Tuebingen, Germany; Section on Experimental Radiology, Department of Diagnostic and Interventional Radiology, University of Tuebingen, Germany
| | - Fritz Schick
- Section on Experimental Radiology, Department of Diagnostic and Interventional Radiology, University of Tuebingen, Germany
| | - Lutz Birnbaumer
- Neurobiology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Durham, NC, USA; Institute of Biomedical Research (BIOMED), Catholic University of Argentina, Buenos Aires, Argentina
| | - Hans-Ulrich Häring
- Department of Internal Medicine, Division of Endocrinology, Diabetology, Vascular Disease, Nephrology and Clinical Chemistry, University of Tuebingen, Tuebingen, Germany; German Center for Diabetes Research (DZD), Neuherberg, Germany; Institute for Diabetes Research and Metabolic Diseases of the Helmholtz Center Munich at the University of Tuebingen (IDM), Tuebingen, Germany
| | - Alexander Pfeifer
- Institute of Pharmacology and Toxicology, University of Bonn, 53127, Bonn, Germany
| | - Bernd Nürnberg
- Department of Pharmacology, Experimental Therapy and Toxicology and Interfaculty Center of Pharmacoge-nomics and Drug Research, University of Tübingen, 72074, Tübingen, Germany.
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14
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Vega SC, Leiss V, Piekorz R, Calaminus C, Pexa K, Vuozzo M, Schmid AM, Devanathan V, Kesenheimer C, Pichler BJ, Beer-Hammer S, Nürnberg B. Selective protection of murine cerebral G i/o-proteins from inactivation by parenterally injected pertussis toxin. J Mol Med (Berl) 2019; 98:97-110. [PMID: 31811326 DOI: 10.1007/s00109-019-01854-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2018] [Revised: 10/30/2019] [Accepted: 11/12/2019] [Indexed: 12/18/2022]
Abstract
Pertussis toxin (PTX) is a potent virulence factor in patients suffering from whooping cough, but in its detoxified version, it is applied for vaccination. It is thought to contribute to the pathology of the disease including various CNS malfunctions. Based on its enzymatic activity, PTX disrupts GPCR-dependent signaling by modifying the α-subunit of heterotrimeric Gi/o-proteins. It is also extensively used as a research tool to study neuronal functions in vivo and in vitro. However, data demonstrating the penetration of PTX from the blood into the brain are missing. Here, we examined the Gαi/o-modifying activity of PTX in murine brains after its parenteral application. Ex vivo biodistribution analysis of [124I]-PTX displayed poor distribution to the brain while relatively high concentrations were visible in the pancreas. PTX affected CNS and endocrine functions of the pancreas as shown by open-field and glucose tolerance tests, respectively. However, while pancreatic islet Gαi/o-proteins were modified, their neuronal counterparts in brain tissue were resistant towards PTX as indicated by different autoradiographic and immunoblot SDS-PAGE analyses. In contrast, PTX easily modified brain Gαi/o-proteins ex vivo. An attempt to increase BBB permeability by application of hypertonic mannitol did not show PTX activity on neuronal G proteins. Consistent with these findings, in vivo MRI analysis did not point to an increased blood-brain barrier (BBB) permeability following PTX treatment. Our data demonstrate that the CNS is protected from PTX. Thus, we hypothesize that the BBB hinders PTX to penetrate into the CNS and to deliver its enzymatic activity to brain Gαi/o-proteins. KEY MESSAGES: i.p. applied PTX is poorly retained in the brain while reaches high concentration in the pancreas. Pancreatic islet Gαi/o- but not cerebral Gαi/o-proteins are modified by i.p. administered PTX. Gαi/o-proteins from isolated cerebral cell membranes were easily modified by PTX ex vivo. CNS is protected from i.p. administered PTX. PTX does not permeabilize the BBB.
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Affiliation(s)
- Salvador Castaneda Vega
- Werner Siemens Imaging Center, Department of Preclinical Imaging and Radiopharmacy, Eberhard Karls University Tübingen and University Medical Center, Tübingen, Germany
- Department of Nuclear Medicine and Clinical Molecular Imaging, Eberhard Karls University, Tübingen, Germany
| | - Veronika Leiss
- Department of Pharmacology and Experimental Therapy, Institute for Experimental and Clinical Pharmacology and Toxicology, Interfaculty Center for Pharmacogenomics and Drug Research, Eberhard Karls University Tübingen, 72074, Tübingen, Germany
| | - Roland Piekorz
- Institute for Biochemistry and Molecular Biology II, Medical Faculty, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Carsten Calaminus
- Werner Siemens Imaging Center, Department of Preclinical Imaging and Radiopharmacy, Eberhard Karls University Tübingen and University Medical Center, Tübingen, Germany
| | - Katja Pexa
- Institute for Biochemistry and Molecular Biology II, Medical Faculty, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Marta Vuozzo
- Werner Siemens Imaging Center, Department of Preclinical Imaging and Radiopharmacy, Eberhard Karls University Tübingen and University Medical Center, Tübingen, Germany
| | - Andreas M Schmid
- Werner Siemens Imaging Center, Department of Preclinical Imaging and Radiopharmacy, Eberhard Karls University Tübingen and University Medical Center, Tübingen, Germany
| | - Vasudharani Devanathan
- Department of Pharmacology and Experimental Therapy, Institute for Experimental and Clinical Pharmacology and Toxicology, Interfaculty Center for Pharmacogenomics and Drug Research, Eberhard Karls University Tübingen, 72074, Tübingen, Germany
- Neuroscience Lab, Department of Biology, Indian Institute of Science Education and Research (IISER), Tirupati, India
| | - Christian Kesenheimer
- Werner Siemens Imaging Center, Department of Preclinical Imaging and Radiopharmacy, Eberhard Karls University Tübingen and University Medical Center, Tübingen, Germany
| | - Bernd J Pichler
- Werner Siemens Imaging Center, Department of Preclinical Imaging and Radiopharmacy, Eberhard Karls University Tübingen and University Medical Center, Tübingen, Germany
- Department of Nuclear Medicine and Clinical Molecular Imaging, Eberhard Karls University, Tübingen, Germany
| | - Sandra Beer-Hammer
- Department of Pharmacology and Experimental Therapy, Institute for Experimental and Clinical Pharmacology and Toxicology, Interfaculty Center for Pharmacogenomics and Drug Research, Eberhard Karls University Tübingen, 72074, Tübingen, Germany
| | - Bernd Nürnberg
- Department of Pharmacology and Experimental Therapy, Institute for Experimental and Clinical Pharmacology and Toxicology, Interfaculty Center for Pharmacogenomics and Drug Research, Eberhard Karls University Tübingen, 72074, Tübingen, Germany.
- Department of Toxicology, Institute for Experimental and Clinical Pharmacology and Toxicology, Eberhard Karls University Tübingen, and University Medical Center, Tübingen, Germany.
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15
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Sun Q, He Q, Xu J, Liu Q, Lu Y, Zhang Z, Xu X, Sun B. Guanine nucleotide-binding protein G(i)α2 aggravates hepatic ischemia-reperfusion injury in mice by regulating MLK3 signaling. FASEB J 2019; 33:7049-7060. [PMID: 30840837 DOI: 10.1096/fj.201802462r] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2023]
Abstract
Hepatic ischemia-reperfusion (I/R) injury is a major challenge in liver resection and transplantation surgeries. Previous studies have revealed that guanine nucleotide-binding protein G(i)α2 (GNAI2) was involved in the progression of myocardial and cerebral I/R injury, but the role and function of GNAI2 in hepatic I/R have not been elucidated. The hepatocyte-specific GNAI2 knockout (GNAI2hep-/-) mice were generated and subjected to hepatic I/R injury. Primary hepatocytes isolated from GNAI2hep-/- and GNAI2flox/flox mice were cultured and challenged to hypoxia-reoxygenation insult. The specific function of GNAI2 in I/R-triggered hepatic injury and the underlying molecular mechanism were explored by various phenotypic analyses and molecular biology methods. In this study, we demonstrated that hepatic GNAI2 expression was significantly increased in liver transplantation patients and wild-type mice after hepatic I/R. Interestingly, hepatocyte-specific GNAI2 deficiency attenuated I/R-induced liver damage, inflammation cytokine expression, macrophage/neutrophil infiltration, and hepatocyte apoptosis in vivo and in vitro. Mechanistically, up-regulation of GNAI2 phosphorylates mixed-lineage protein kinase 3 (MLK3) through direct binding, which exacerbated hepatic I/R damage via MAPK and NF-κB pathway activation. Furthermore, blocking MLK3 signaling reversed GNAI2-mediated hepatic I/R injury. Our study firstly identifies GNAI2 as a promising target for prevention of hepatic I/R-induced injury and related liver diseases.-Sun, Q., He, Q., Xu, J., Liu, Q., Lu, Y., Zhang, Z., Xu, X., Sun, B. Guanine nucleotide-binding protein G(i)α2 aggravates hepatic ischemia-reperfusion injury in mice by regulating MLK3 signaling.
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Affiliation(s)
- Qikai Sun
- The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
- Department of Hepatobiliary Surgery, Nanjing Drum Tower Hospital, Clinical College of Nanjing Medical University, Nanjing, China; and
- Department of Hepatobiliary Surgery, The Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, China
| | - Qifeng He
- The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
- Department of Hepatobiliary Surgery, Nanjing Drum Tower Hospital, Clinical College of Nanjing Medical University, Nanjing, China; and
- Department of Hepatobiliary Surgery, The Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, China
| | - Jianbo Xu
- The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
- Department of Hepatobiliary Surgery, Nanjing Drum Tower Hospital, Clinical College of Nanjing Medical University, Nanjing, China; and
- Department of Hepatobiliary Surgery, The Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, China
| | - Qiaoyu Liu
- Department of Hepatobiliary Surgery, Nanjing Drum Tower Hospital, Clinical College of Nanjing Medical University, Nanjing, China; and
- Department of Hepatobiliary Surgery, The Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, China
| | - Yijun Lu
- The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
- Department of Hepatobiliary Surgery, Nanjing Drum Tower Hospital, Clinical College of Nanjing Medical University, Nanjing, China; and
- Department of Hepatobiliary Surgery, The Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, China
| | - Zechuan Zhang
- The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
- Department of Hepatobiliary Surgery, Nanjing Drum Tower Hospital, Clinical College of Nanjing Medical University, Nanjing, China; and
- Department of Hepatobiliary Surgery, The Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, China
| | - Xiaoliang Xu
- Department of Hepatobiliary Surgery, Nanjing Drum Tower Hospital, Clinical College of Nanjing Medical University, Nanjing, China; and
- Department of Hepatobiliary Surgery, The Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, China
| | - Beicheng Sun
- The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
- Department of Hepatobiliary Surgery, Nanjing Drum Tower Hospital, Clinical College of Nanjing Medical University, Nanjing, China; and
- Department of Hepatobiliary Surgery, The Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, China
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16
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Li ZW, Sun B, Gong T, Guo S, Zhang J, Wang J, Sugawara A, Jiang M, Yan J, Gurary A, Zheng X, Gao B, Xiao SY, Chen W, Ma C, Farrar C, Zhu C, Chan OTM, Xin C, Winnicki A, Winnicki J, Tang M, Park R, Winnicki M, Diener K, Wang Z, Liu Q, Chu CH, Arter ZL, Yue P, Alpert L, Hui GS, Fei P, Turkson J, Yang W, Wu G, Tao A, Ramos JW, Moisyadi S, Holcombe RF, Jia W, Birnbaumer L, Zhou X, Chu WM. GNAI1 and GNAI3 Reduce Colitis-Associated Tumorigenesis in Mice by Blocking IL6 Signaling and Down-regulating Expression of GNAI2. Gastroenterology 2019; 156:2297-2312. [PMID: 30836096 PMCID: PMC6628260 DOI: 10.1053/j.gastro.2019.02.040] [Citation(s) in RCA: 68] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/08/2018] [Revised: 02/06/2019] [Accepted: 02/28/2019] [Indexed: 12/12/2022]
Abstract
BACKGROUND & AIMS Interleukin 6 (IL6) and tumor necrosis factor contribute to the development of colitis-associated cancer (CAC). We investigated these signaling pathways and the involvement of G protein subunit alpha i1 (GNAI1), GNAI2, and GNAI3 in the development of CAC in mice and humans. METHODS B6;129 wild-type (control) or mice with disruption of Gnai1, Gnai2, and/or Gnai3 or conditional disruption of Gnai2 in CD11c+ or epithelial cells were given dextran sulfate sodium (DSS) to induce colitis followed by azoxymethane (AOM) to induce carcinogenesis; some mice were given an antibody against IL6. Feces were collected from mice, and the compositions of microbiomes were analyzed by polymerase chain reactions. Dendritic cells (DCs) and myeloid-derived suppressor cells (MDSCs) isolated from spleen and colon tissues were analyzed by flow cytometry. We performed immunoprecipitation and immunoblot analyses of colon tumor tissues, MDSCs, and mouse embryonic fibroblasts to study the expression levels of GNAI1, GNAI2, and GNAI3 and the interactions of GNAI1 and GNAI3 with proteins in the IL6 signaling pathway. We analyzed the expression of Gnai2 messenger RNA by CD11c+ cells in the colonic lamina propria by PrimeFlow, expression of IL6 in DCs by flow cytometry, and secretion of cytokines in sera and colon tissues by enzyme-linked immunosorbent assay. We obtained colon tumor and matched nontumor tissues from 83 patients with colorectal cancer having surgery in China and 35 patients with CAC in the United States. Mouse and human colon tissues were analyzed by histology, immunoblot, immunohistochemistry, and/or RNA-sequencing analyses. RESULTS GNAI1 and GNAI3 (GNAI1;3) double-knockout (DKO) mice developed more severe colitis after administration of DSS and significantly more colonic tumors than control mice after administration of AOM plus DSS. Development of increased tumors in DKO mice was not associated with changes in fecal microbiomes but was associated with activation of nuclear factor (NF) κB and signal transducer and activator of transcription (STAT) 3; increased levels of GNAI2, nitric oxide synthase 2, and IL6; increased numbers of CD4+ DCs and MDSCs; and decreased numbers of CD8+ DCs. IL6 was mainly produced by CD4+/CD11b+, but not CD8+, DCs in DKO mice. Injection of DKO mice with a blocking antibody against IL6 reduced the expansion of MDSCs and the number of tumors that developed after CAC induction. Incubation of MDSCs or mouse embryonic fibroblasts with IL6 induced activation of either NF-κB by a JAK2-TRAF6-TAK1-CHUK/IKKB signaling pathway or STAT3 by JAK2. This activation resulted in expression of GNAI2, IL6 signal transducer (IL6ST, also called GP130) and nitric oxide synthase 2, and expansion of MDSCs; the expression levels of these proteins and expansion of MDSCs were further increased by the absence of GNAI1;3 in cells and mice. Conditional disruption of Gnai2 in CD11c+ cells of DKO mice prevented activation of NF-κB and STAT3 and changes in numbers of DCs and MDSCs. Colon tumor tissues from patients with CAC had reduced levels of GNAI1 and GNAI3 and increased levels of GNAI2 compared with normal tissues. Further analysis of a public human colorectal tumor DNA microarray database (GSE39582) showed that low Gani1 and Gnai3 messenger RNA expression and high Gnai2 messenger RNA expression were significantly associated with decreased relapse-free survival. CONCLUSIONS GNAI1;3 suppresses DSS-plus-AOM-induced colon tumor development in mice, whereas expression of GNAI2 in CD11c+ cells and IL6 in CD4+/CD11b+ DCs appears to promote these effects. Strategies to induce GNAI1;3, or block GNAI2 and IL6, might be developed for the prevention or therapy of CAC in patients.
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Affiliation(s)
- Zhi-Wei Li
- Cancer Biology Program, University of Hawaii Cancer Center, Honolulu, Hawaii
| | - Beicheng Sun
- Department of Hepatobiliary Surgery, The Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, Jiangsu, China
| | - Ting Gong
- Cancer Biology Program, University of Hawaii Cancer Center, Honolulu, Hawaii
| | - Sheng Guo
- Cancer Biology Program, University of Hawaii Cancer Center, Honolulu, Hawaii; Department of Endocrine, Genetics and Metabolism, Shanghai Children's Hospital, Shanghai Jiao Tong University, Shanghai, China
| | - Jianhua Zhang
- Cancer Biology Program, University of Hawaii Cancer Center, Honolulu, Hawaii; Department of Pediatrics, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Junlong Wang
- Cancer Biology Program, University of Hawaii Cancer Center, Honolulu, Hawaii
| | - Atsushi Sugawara
- Institute for Biogenesis Research, John A. Burns School of Medicine, University of Hawaii, Honolulu, Hawaii
| | - Meisheng Jiang
- Department of Molecular and Medical Pharmacology, University of California, Los Angeles, California
| | - Junjun Yan
- Department of Gastroenterology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu, China
| | - Alexandra Gurary
- Department of Tropical Medicine, Medical Microbiology, and Pharmacology, John A. Burns School of Medicine, University of Hawaii, Honolulu, Hawaii
| | - Xin Zheng
- Cancer Biology Program, University of Hawaii Cancer Center, Honolulu, Hawaii
| | - Bifeng Gao
- Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, Colorado
| | - Shu-Yuan Xiao
- Department of Pathology, Zhongnan Hospital of Wuhan University, Wuhan, Hubei, China; Department of Pathology, University of Chicago, Chicago, Illinois
| | - Wenlian Chen
- Epidemiology Program, University of Hawaii Cancer Center, Honolulu, Hawaii
| | - Chi Ma
- Cancer Biology Program, University of Hawaii Cancer Center, Honolulu, Hawaii
| | - Christine Farrar
- The Microscopy, Imaging, and Flow Cytometry Shared Resource, University of Hawaii Cancer Center, Honolulu, Hawaii
| | - Chenjun Zhu
- Cancer Biology Program, University of Hawaii Cancer Center, Honolulu, Hawaii
| | - Owen T M Chan
- Pathology Core, University of Hawaii Cancer Center, Honolulu, Hawaii
| | - Can Xin
- Cancer Biology Program, University of Hawaii Cancer Center, Honolulu, Hawaii
| | - Andrew Winnicki
- Cancer Biology Program, University of Hawaii Cancer Center, Honolulu, Hawaii
| | - John Winnicki
- Cancer Biology Program, University of Hawaii Cancer Center, Honolulu, Hawaii
| | - Mingxin Tang
- Center for Cardiovascular Research, John A. Burns School of Medicine, University of Hawaii, Honolulu, Hawaii
| | - Ryan Park
- Cancer Biology Program, University of Hawaii Cancer Center, Honolulu, Hawaii
| | - Mary Winnicki
- Cancer Biology Program, University of Hawaii Cancer Center, Honolulu, Hawaii
| | - Katrina Diener
- Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, Colorado
| | - Zhanwei Wang
- Cancer Biology Program, University of Hawaii Cancer Center, Honolulu, Hawaii
| | - Qicai Liu
- Cancer Biology Program, University of Hawaii Cancer Center, Honolulu, Hawaii; Department of Cardiology and Heart Center, Zhujiang Hospital, Southern Medical University, Guangzhou, Guangdong, China
| | - Catherine H Chu
- Cancer Biology Program, University of Hawaii Cancer Center, Honolulu, Hawaii
| | - Zhaohui L Arter
- Cancer Biology Program, University of Hawaii Cancer Center, Honolulu, Hawaii
| | - Peibin Yue
- Cancer Biology Program, University of Hawaii Cancer Center, Honolulu, Hawaii
| | - Lindsay Alpert
- Department of Pathology, University of Chicago, Chicago, Illinois
| | - George S Hui
- Department of Tropical Medicine, Medical Microbiology, and Pharmacology, John A. Burns School of Medicine, University of Hawaii, Honolulu, Hawaii
| | - Peiwen Fei
- Cancer Biology Program, University of Hawaii Cancer Center, Honolulu, Hawaii
| | - James Turkson
- Cancer Biology Program, University of Hawaii Cancer Center, Honolulu, Hawaii
| | - Wentian Yang
- Department of Orthopedics, Rhode Island Hospital, Brown University Alpert Medical School, Providence, Rhode Island
| | - Guangyu Wu
- Department of Pharmacology and Toxicology, Augusta University, Augusta, Georgia
| | - Ailin Tao
- The Second Affiliated Hospital, The State Key Laboratory of Respiratory Disease, Guangdong Provincial Key Laboratory of Allergy and Clinical Immunology, Guangzhou Medical University, Guangzhou, Guangdong, China
| | - Joe W Ramos
- Cancer Biology Program, University of Hawaii Cancer Center, Honolulu, Hawaii
| | - Stefan Moisyadi
- Institute for Biogenesis Research, John A. Burns School of Medicine, University of Hawaii, Honolulu, Hawaii
| | - Randall F Holcombe
- Cancer Biology Program, University of Hawaii Cancer Center, Honolulu, Hawaii
| | - Wei Jia
- Epidemiology Program, University of Hawaii Cancer Center, Honolulu, Hawaii
| | - Lutz Birnbaumer
- Neurobiology Laboratory, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina; Institute for Biomedical Research (BIOMED), Universidad Católica Argentina, Buenos Aires, Argentina
| | - Xiqiao Zhou
- Department of Gastroenterology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu, China.
| | - Wen-Ming Chu
- Cancer Biology Program, University of Hawaii Cancer Center, Honolulu, Hawaii; The Second Affiliated Hospital, The State Key Laboratory of Respiratory Disease, Guangdong Provincial Key Laboratory of Allergy and Clinical Immunology, Guangzhou Medical University, Guangzhou, Guangdong, China.
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Marivin A, Morozova V, Walawalkar I, Leyme A, Kretov DA, Cifuentes D, Dominguez I, Garcia-Marcos M. GPCR-independent activation of G proteins promotes apical cell constriction in vivo. J Cell Biol 2019; 218:1743-1763. [PMID: 30948426 PMCID: PMC6504902 DOI: 10.1083/jcb.201811174] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Revised: 01/19/2019] [Accepted: 03/12/2019] [Indexed: 01/21/2023] Open
Abstract
Heterotrimeric G proteins are signaling switches that control organismal morphogenesis across metazoans. In invertebrates, specific GPCRs instruct G proteins to promote collective apical cell constriction in the context of epithelial tissue morphogenesis. In contrast, tissue-specific factors that instruct G proteins during analogous processes in vertebrates are largely unknown. Here, we show that DAPLE, a non-GPCR protein linked to human neurodevelopmental disorders, is expressed specifically in the neural plate of Xenopus laevis embryos to trigger a G protein signaling pathway that promotes apical cell constriction during neurulation. DAPLE localizes to apical cell-cell junctions in the neuroepithelium, where it activates G protein signaling to drive actomyosin-dependent apical constriction and subsequent bending of the neural plate. This function is mediated by a Gα-binding-and-activating (GBA) motif that was acquired by DAPLE in vertebrates during evolution. These findings reveal that regulation of tissue remodeling during vertebrate development can be driven by an unconventional mechanism of heterotrimeric G protein activation that operates in lieu of GPCRs.
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Affiliation(s)
- Arthur Marivin
- Department of Biochemistry, Boston University School of Medicine, Boston, MA
| | - Veronika Morozova
- Department of Biochemistry, Boston University School of Medicine, Boston, MA
| | - Isha Walawalkar
- Department of Biochemistry, Boston University School of Medicine, Boston, MA
| | - Anthony Leyme
- Department of Biochemistry, Boston University School of Medicine, Boston, MA
| | - Dmitry A Kretov
- Department of Biochemistry, Boston University School of Medicine, Boston, MA
| | - Daniel Cifuentes
- Department of Biochemistry, Boston University School of Medicine, Boston, MA
| | - Isabel Dominguez
- Department of Medicine, Boston University School of Medicine, Boston, MA
| | - Mikel Garcia-Marcos
- Department of Biochemistry, Boston University School of Medicine, Boston, MA
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18
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Vural A, Nabar NR, Hwang IY, Sohn S, Park C, Karlsson MCI, Blumer JB, Kehrl JH. Gα i2 Signaling Regulates Inflammasome Priming and Cytokine Production by Biasing Macrophage Phenotype Determination. THE JOURNAL OF IMMUNOLOGY 2019; 202:1510-1520. [PMID: 30683698 DOI: 10.4049/jimmunol.1801145] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2018] [Accepted: 12/19/2018] [Indexed: 12/14/2022]
Abstract
Macrophages exist as innate immune subsets that exhibit phenotypic heterogeneity and functional plasticity. Their phenotypes are dictated by inputs from the tissue microenvironment. G-protein-coupled receptors are essential in transducing signals from the microenvironment, and heterotrimeric Gα signaling links these receptors to downstream effectors. Several Gαi-coupled G-protein-coupled receptors have been implicated in macrophage polarization. In this study, we use genetically modified mice to investigate the role of Gαi2 on inflammasome activity and macrophage polarization. We report that Gαi2 in murine bone marrow-derived macrophages (BMDMs) regulates IL-1β release after activation of the NLRP3, AIM2, and NLRC4 inflammasomes. We show this regulation stems from the biased polarity of Gαi2 deficient (Gnai2 -/-) and RGS-insensitive Gαi2 (Gnai2 G184S/G184S) BMDMs. We determined that although Gnai2 G184S/G184S BMDMs (excess Gαi2 signaling) have a tendency toward classically activated proinflammatory (M1) phenotype, Gnai2-/- BMDMs (Gαi2 deficient) are biased toward alternatively activated anti-inflammatory (M2) phenotype. Finally, we find that Gαi2-deficient macrophages have increased Akt activation and IFN-β production but defects in ERK1/2 and STAT3 activation after LPS stimulation. Gαi2-deficient macrophages also exhibit increased STAT6 activation after IL-4 stimulation. In summary, our data indicates that excess Gαi2 signaling promotes an M1 macrophage phenotype, whereas Gαi2 signaling deficiency promotes an M2 phenotype. Understanding Gαi2-mediated effects on macrophage polarization may bring to light insights regarding disease pathogenesis and the reprogramming of macrophages for the development of novel therapeutics.
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Affiliation(s)
- Ali Vural
- B-Cell Molecular Immunology Section, Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892
| | - Neel R Nabar
- B-Cell Molecular Immunology Section, Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892; .,Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, 171 77 Stockholm, Sweden; and
| | - Il-Young Hwang
- B-Cell Molecular Immunology Section, Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892
| | - Silke Sohn
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, 171 77 Stockholm, Sweden; and
| | - Chung Park
- B-Cell Molecular Immunology Section, Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892
| | - Mikael C I Karlsson
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, 171 77 Stockholm, Sweden; and
| | - Joe B Blumer
- Department of Cell and Molecular Pharmacology and Experimental Therapeutics, Medical University of South Carolina, Charleston, SC 29425
| | - John H Kehrl
- B-Cell Molecular Immunology Section, Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892;
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Gα i3 signaling is associated with sexual dimorphic expression of the clock-controlled output gene Dbp in murine liver. Oncotarget 2018; 9:30213-30224. [PMID: 30100984 PMCID: PMC6084400 DOI: 10.18632/oncotarget.25727] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2017] [Accepted: 06/14/2018] [Indexed: 11/25/2022] Open
Abstract
The albumin D-box binding protein (DBP) is a member of the PAR bZip (proline and acidic amino acid-rich basic leucine zipper) transcription factor family and functions as important regulator of circadian core and output gene expression. Gene expression of DBP itself is under the control of E-box-dependent binding by the Bmal1-Clock heterodimer and CRE-dependent binding by the cAMP responsive element binding protein (CREB). However, the signaling mechanism mediating CREB-dependent regulation of DBP expression in the peripheral clock remains elusive. In this study, we examined the role of the GPCR (G-protein-coupled receptor)/Gαi3 (Galphai3) controlled cAMP-CREB signaling pathway in the regulation of hepatic expression of core clock and clock-regulated genes, including Dbp. Analysis of circadian gene expression revealed that rhythmicity of hepatic transcript levels of the majority of core clock (including Per1) and clock-regulated genes were not affected by Gαi3 deficiency. Consistently, the period length of primary Gαi3 deficient tail fibroblasts expressing a Bmal1-Luciferase reporter was not affected. Interestingly, however, Gαi3 deficient female but not male mice showed a tendentiously increased activation of CREB (nuclear pSer133-CREB) accompanied by an advanced peak in Dbp gene expression and elevated mRNA levels of the cytochrome P450 family member Cyp3a11, a target gene of DBP. Accordingly, selective inhibition of CREB led to a strongly decreased expression of DBP and CYP3A4 (human Cyp3a11 homologue) in HepG2 liver cells. In summary, our data suggest that the Gαi3-pCREB signalling pathway functions as a regulator of sexual-dimorphic expression of DBP and its xenobiotic target enzymes Cyp3a11/CYP3A4.
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20
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Squires KE, Montañez-Miranda C, Pandya RR, Torres MP, Hepler JR. Genetic Analysis of Rare Human Variants of Regulators of G Protein Signaling Proteins and Their Role in Human Physiology and Disease. Pharmacol Rev 2018; 70:446-474. [PMID: 29871944 PMCID: PMC5989036 DOI: 10.1124/pr.117.015354] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Regulators of G protein signaling (RGS) proteins modulate the physiologic actions of many neurotransmitters, hormones, and other signaling molecules. Human RGS proteins comprise a family of 20 canonical proteins that bind directly to G protein-coupled receptors/G protein complexes to limit the lifetime of their signaling events, which regulate all aspects of cell and organ physiology. Genetic variations account for diverse human traits and individual predispositions to disease. RGS proteins contribute to many complex polygenic human traits and pathologies such as hypertension, atherosclerosis, schizophrenia, depression, addiction, cancers, and many others. Recent analysis indicates that most human diseases are due to extremely rare genetic variants. In this study, we summarize physiologic roles for RGS proteins and links to human diseases/traits and report rare variants found within each human RGS protein exome sequence derived from global population studies. Each RGS sequence is analyzed using recently described bioinformatics and proteomic tools for measures of missense tolerance ratio paired with combined annotation-dependent depletion scores, and protein post-translational modification (PTM) alignment cluster analysis. We highlight selected variants within the well-studied RGS domain that likely disrupt RGS protein functions and provide comprehensive variant and PTM data for each RGS protein for future study. We propose that rare variants in functionally sensitive regions of RGS proteins confer profound change-of-function phenotypes that may contribute, in newly appreciated ways, to complex human diseases and/or traits. This information provides investigators with a valuable database to explore variation in RGS protein function, and for targeting RGS proteins as future therapeutic targets.
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Affiliation(s)
- Katherine E Squires
- Department of Pharmacology, Emory University School of Medicine, Atlanta, Georgia (K.E.S., C.M.-M., J.R.H.); and School of Biological Sciences, Georgia Institute of Technology, Atlanta, Georgia (R.R.P., M.P.T.)
| | - Carolina Montañez-Miranda
- Department of Pharmacology, Emory University School of Medicine, Atlanta, Georgia (K.E.S., C.M.-M., J.R.H.); and School of Biological Sciences, Georgia Institute of Technology, Atlanta, Georgia (R.R.P., M.P.T.)
| | - Rushika R Pandya
- Department of Pharmacology, Emory University School of Medicine, Atlanta, Georgia (K.E.S., C.M.-M., J.R.H.); and School of Biological Sciences, Georgia Institute of Technology, Atlanta, Georgia (R.R.P., M.P.T.)
| | - Matthew P Torres
- Department of Pharmacology, Emory University School of Medicine, Atlanta, Georgia (K.E.S., C.M.-M., J.R.H.); and School of Biological Sciences, Georgia Institute of Technology, Atlanta, Georgia (R.R.P., M.P.T.)
| | - John R Hepler
- Department of Pharmacology, Emory University School of Medicine, Atlanta, Georgia (K.E.S., C.M.-M., J.R.H.); and School of Biological Sciences, Georgia Institute of Technology, Atlanta, Georgia (R.R.P., M.P.T.)
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21
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Beer-Hammer S, Lee SC, Mauriac SA, Leiss V, Groh IAM, Novakovic A, Piekorz RP, Bucher K, Chen C, Ni K, Singer W, Harasztosi C, Schimmang T, Zimmermann U, Pfeffer K, Birnbaumer L, Forge A, Montcouquiol M, Knipper M, Nürnberg B, Rüttiger L. Gαi Proteins are Indispensable for Hearing. Cell Physiol Biochem 2018; 47:1509-1532. [PMID: 29940568 PMCID: PMC11825972 DOI: 10.1159/000490867] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2018] [Accepted: 04/24/2018] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND/AIMS From invertebrates to mammals, Gαi proteins act together with their common binding partner Gpsm2 to govern cell polarization and planar organization in virtually any polarized cell. Recently, we demonstrated that Gαi3-deficiency in pre-hearing murine cochleae pointed to a role of Gαi3 for asymmetric migration of the kinocilium as well as the orientation and shape of the stereociliary ("hair") bundle, a requirement for the progression of mature hearing. We found that the lack of Gαi3 impairs stereociliary elongation and hair bundle shape in high-frequency cochlear regions, linked to elevated hearing thresholds for high-frequency sound. How these morphological defects translate into hearing phenotypes is not clear. METHODS Here, we studied global and conditional Gnai3 and Gnai2 mouse mutants deficient for either one or both Gαi proteins. Comparative analyses of global versus Foxg1-driven conditional mutants that mainly delete in the inner ear and telencephalon in combination with functional tests were applied to dissect essential and redundant functions of different Gαi isoforms and to assign specific defects to outer or inner hair cells, the auditory nerve, satellite cells or central auditory neurons. RESULTS Here we report that lack of Gαi3 but not of the ubiquitously expressed Gαi2 elevates hearing threshold, accompanied by impaired hair bundle elongation and shape in high-frequency cochlear regions. During the crucial reprogramming of the immature inner hair cell (IHC) synapse into a functional sensory synapse of the mature IHC deficiency for Gαi2 or Gαi3 had no impact. In contrast, double-deficiency for Gαi2 and Gαi3 isoforms results in abnormalities along the entire tonotopic axis including profound deafness associated with stereocilia defects. In these mice, postnatal IHC synapse maturation is also impaired. In addition, the analysis of conditional versus global Gαi3-deficient mice revealed that the amplitude of ABR wave IV was disproportionally elevated in comparison to ABR wave I indicating that Gαi3 is selectively involved in generation of neural gain during auditory processing. CONCLUSION We propose a so far unrecognized complexity of isoform-specific and overlapping Gαi protein functions particular during final differentiation processes.
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Affiliation(s)
- Sandra Beer-Hammer
- Department of Pharmacology and Experimental Therapy, and Interfaculty Center of Pharmacogenomics and Drug Research (ICePhA), University of Tübingen, Tübingen, Germany
| | - Sze Chim Lee
- Molecular Physiology of Hearing, Tübingen Hearing Research Centre, Department of Otolaryngology, University of Tübingen, Tübingen, Germany
| | - Stephanie A. Mauriac
- INSERM, Neurocentre Magendie, U1215, 146 rue Leo-Saignat, Bordeaux
- University of Bordeaux, Neurocentre Magendie, Bordeaux, France
| | - Veronika Leiss
- Department of Pharmacology and Experimental Therapy, and Interfaculty Center of Pharmacogenomics and Drug Research (ICePhA), University of Tübingen, Tübingen, Germany
| | - Isabel A. M. Groh
- Department of Pharmacology and Experimental Therapy, and Interfaculty Center of Pharmacogenomics and Drug Research (ICePhA), University of Tübingen, Tübingen, Germany
| | - Ana Novakovic
- Department of Pharmacology and Experimental Therapy, and Interfaculty Center of Pharmacogenomics and Drug Research (ICePhA), University of Tübingen, Tübingen, Germany
| | - Roland P. Piekorz
- Institute for Biochemistry and Molecular Biology II, Medical Faculty, University of Düsseldorf, Düsseldorf, Germany
| | - Kirsten Bucher
- Department of Pharmacology and Experimental Therapy, and Interfaculty Center of Pharmacogenomics and Drug Research (ICePhA), University of Tübingen, Tübingen, Germany
| | - Chengfang Chen
- Molecular Physiology of Hearing, Tübingen Hearing Research Centre, Department of Otolaryngology, University of Tübingen, Tübingen, Germany
| | - Kun Ni
- Molecular Physiology of Hearing, Tübingen Hearing Research Centre, Department of Otolaryngology, University of Tübingen, Tübingen, Germany
| | - Wibke Singer
- Molecular Physiology of Hearing, Tübingen Hearing Research Centre, Department of Otolaryngology, University of Tübingen, Tübingen, Germany
| | - Csaba Harasztosi
- Department of Otolaryngology, Tübingen Hearing Research Center, Section of Physiological Acoustics and Communication, University of Tübingen, Tübingen, Germany
| | - Thomas Schimmang
- Instituto de Biologíay Genética Molecular, Universidad de Valladolid y Consejo Superior de Investigaciones Científicas, Valladolid, Spain
| | - Ulrike Zimmermann
- Molecular Physiology of Hearing, Tübingen Hearing Research Centre, Department of Otolaryngology, University of Tübingen, Tübingen, Germany
| | - Klaus Pfeffer
- Institute of Medical Microbiology and Hospital Hygiene, University of Düsseldorf, Düsseldorf, Germany
| | - Lutz Birnbaumer
- Neurobiology Laboratory, National Institute of Environmental Health Sciences, National Institute of Health, Research Triangle Park, USA
- Institute of Biomedical Research (BIOMED), School of Medical Sciences, Catholic University of Argentina, Buenos Aires, Argentina
| | | | - Mireille Montcouquiol
- INSERM, Neurocentre Magendie, U1215, 146 rue Leo-Saignat, Bordeaux
- University of Bordeaux, Neurocentre Magendie, Bordeaux, France
| | - Marlies Knipper
- Molecular Physiology of Hearing, Tübingen Hearing Research Centre, Department of Otolaryngology, University of Tübingen, Tübingen, Germany
| | - Bernd Nürnberg
- Department of Pharmacology and Experimental Therapy, and Interfaculty Center of Pharmacogenomics and Drug Research (ICePhA), University of Tübingen, Tübingen, Germany
| | - Lukas Rüttiger
- Molecular Physiology of Hearing, Tübingen Hearing Research Centre, Department of Otolaryngology, University of Tübingen, Tübingen, Germany
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Loss of Gα i proteins impairs thymocyte development, disrupts T-cell trafficking, and leads to an expanded population of splenic CD4 +PD-1 +CXCR5 +/- T-cells. Sci Rep 2017. [PMID: 28646160 PMCID: PMC5482867 DOI: 10.1038/s41598-017-04537-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Thymocyte and T cell trafficking relies on signals initiated by G-protein coupled receptors. To address the importance of the G-proteins Gαi2 and Gαi3 in thymocyte and T cell function, we developed several mouse models. Gαi2 deficiency in hematopoietic progenitors led to a small thymus, a double negative (DN)1/DN2 thymocyte transition block, and an accumulation of mature single positive (SP) thymocytes. Loss at the double positive (DP) stage of thymocyte development caused an increase in mature cells within the thymus. In both models an abnormal distribution of memory and naïve CD4 T cells occurred, and peripheral CD4 and CD8 T cells had reduced chemoattractant responses. The loss of Gαi3 had no discernable impact, however the lack of both G-proteins commencing at the DP stage caused a severe T cell phenotype. These mice lacked a thymic medullary region, exhibited thymocyte retention, had a peripheral T cell deficiency, and lacked T cell chemoattractant responses. Yet a noteworthy population of CD4+PD-1+CXCR5+/− cells resided in the spleen of these mice likely due to a loss of regulatory T cell function. Our results delineate a role for Gαi2 in early thymocyte development and for Gαi2/3 in multiple aspects of T cell biology.
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Role of GATA binding protein 4 (GATA4) in the regulation of tooth development via GNAI3. Sci Rep 2017; 7:1534. [PMID: 28484278 PMCID: PMC5431507 DOI: 10.1038/s41598-017-01689-1] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2016] [Accepted: 03/31/2017] [Indexed: 12/22/2022] Open
Abstract
Transcription factor GATA4 regulates cardiac and osteoblast differentiation. However, its role in tooth development is not clear. Therefore, we generated Wnt1-Cre;GATA4fl/fl mice, with conditional inactivation of the GATA4 gene in the dental papilla mesenchymal cells. Phenotypic analysis showed short root deformity along with reduced expressions of odonto/osteogenic markers. Proliferation (but not apoptosis) of cells around the apical area of the root was attenuated. In vitro, we knocked down GATA4 expression in stem cells of dental apical papilla (SCAPs). Proliferation, migration and odonto/osteogenic differentiation of SCAPs were affected in the shGATA4 group. Overexpression of GATA4 in SCAPs increased mineralization. Based on our previous iTRAQ results, guanine nucleotide binding proteins 3 (GNAI3) is one of the distinct proteins after GATA4 deletion. G protein signaling is involved in bone development, remodeling, and disease. In this study, both GATA4 deletion in the mouse root and knock-down in human SCAPs decreased the expression of GNAI3. Dual-luciferase and ChIP assay confirmed the direct binding of GATA4 to the GNAI3 promoter, both in vitro and in vivo. GNAI3 knock-down significantly decreased the odonto/osteogenic differentiation ability of SCAPs. We thus establish the role of GATA4 as a novel regulator of root development and elucidate its downstream molecular events.
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24
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Diez-Alarcia R, Ibarra-Lecue I, Lopez-Cardona ÁP, Meana J, Gutierrez-Adán A, Callado LF, Agirregoitia E, Urigüen L. Biased Agonism of Three Different Cannabinoid Receptor Agonists in Mouse Brain Cortex. Front Pharmacol 2016; 7:415. [PMID: 27867358 PMCID: PMC5095132 DOI: 10.3389/fphar.2016.00415] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2016] [Accepted: 10/19/2016] [Indexed: 12/29/2022] Open
Abstract
Cannabinoid receptors are able to couple to different families of G proteins when activated by an agonist drug. It has been suggested that different intracellular responses may be activated depending on the ligand. The goal of the present study was to characterize the pattern of G protein subunit stimulation triggered by three different cannabinoid ligands, Δ9-THC, WIN55212-2, and ACEA in mouse brain cortex. Stimulation of the [35S]GTPγS binding coupled to specific immunoprecipitation with antibodies against different subtypes of G proteins (Gαi1, Gαi2, Gαi3, Gαo, Gαz, Gαs, Gαq/11, and Gα12/13), in the presence of Δ9-THC, WIN55212-2 and ACEA (submaximal concentration 10 μM) was determined by scintillation proximity assay (SPA) technique in mouse cortex of wild type, CB1 knock-out, CB2 knock-out and CB1/CB2 double knock-out mice. Results show that, in mouse brain cortex, cannabinoid agonists are able to significantly stimulate not only the classical inhibitory Gαi/o subunits but also other G subunits like Gαz, Gαq/11, and Gα12/13. Moreover, the specific pattern of G protein subunit activation is different depending on the ligand. In conclusion, our results demonstrate that, in mice brain native tissue, different exogenous cannabinoid ligands are able to selectively activate different inhibitory and non-inhibitory Gα protein subtypes, through the activation of CB1 and/or CB2 receptors. Results of the present study may help to understand the specific molecular pathways involved in the pharmacological effects of cannabinoid-derived drugs.
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Affiliation(s)
- Rebeca Diez-Alarcia
- Department of Pharmacology, University of the Basque Country UPV/EHULeioa, Spain; Centro de Investigación Biomédica en Red de Salud MentalMadrid, Spain
| | - Inés Ibarra-Lecue
- Department of Pharmacology, University of the Basque Country UPV/EHU Leioa, Spain
| | - Ángela P Lopez-Cardona
- Department of Animal Reproduction, Instituto Nacional de Tecnología Agraria y AlimentariaMadrid, Spain; G.I. Biogénesis, Universidad de AntioquiaAntioquia, Colombia
| | - Javier Meana
- Department of Pharmacology, University of the Basque Country UPV/EHULeioa, Spain; Centro de Investigación Biomédica en Red de Salud MentalMadrid, Spain
| | - Alfonso Gutierrez-Adán
- Department of Animal Reproduction, Instituto Nacional de Tecnología Agraria y Alimentaria Madrid, Spain
| | - Luis F Callado
- Department of Pharmacology, University of the Basque Country UPV/EHULeioa, Spain; Centro de Investigación Biomédica en Red de Salud MentalMadrid, Spain
| | | | - Leyre Urigüen
- Department of Pharmacology, University of the Basque Country UPV/EHULeioa, Spain; Centro de Investigación Biomédica en Red de Salud MentalMadrid, Spain
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Villanueva H, Visbal AP, Obeid NF, Ta AQ, Faruki AA, Wu MF, Hilsenbeck SG, Shaw CA, Yu P, Plummer NW, Birnbaumer L, Lewis MT. An essential role for Gα(i2) in Smoothened-stimulated epithelial cell proliferation in the mammary gland. Sci Signal 2015; 8:ra92. [PMID: 26373672 DOI: 10.1126/scisignal.aaa7355] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Hedgehog (Hh) signaling is critical for organogenesis, tissue homeostasis, and stem cell maintenance. The gene encoding Smoothened (SMO), the primary effector of Hh signaling, is expressed aberrantly in human breast cancer, as well as in other cancers. In mice that express a constitutively active form of SMO that does not require Hh stimulation in mammary glands, the cells near the transgenic cells proliferate and participate in hyperplasia formation. Although SMO is a seven-transmembrane receptor like G protein-coupled receptors (GPCRs), SMO-mediated activation of the Gli family of transcription factors is not known to involve G proteins. However, data from Drosophila and mammalian cell lines indicate that SMO functions as a GPCR that couples to heterotrimeric G proteins of the pertussis toxin (PTX)-sensitive Gαi class. Using genetically modified mice, we demonstrated that SMO signaling through G proteins occurred in the mammary gland in vivo. SMO-induced stimulation of proliferation was PTX-sensitive and required Gαi2, but not Gαi1, Gαi3, or activation of Gli1 or Gli2. Our findings show that activated SMO functions as a GPCR to stimulate proliferation in vivo, a finding that may have clinical importance because most SMO-targeted agents have been selected based largely on their ability to block Gli-mediated transcription.
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Affiliation(s)
- Hugo Villanueva
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX 77030, USA. Lester and Sue Smith Breast Center, Baylor College of Medicine, Houston, TX 77030, USA
| | - Adriana P Visbal
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX 77030, USA. Lester and Sue Smith Breast Center, Baylor College of Medicine, Houston, TX 77030, USA
| | - Nadine F Obeid
- Lester and Sue Smith Breast Center, Baylor College of Medicine, Houston, TX 77030, USA
| | - Andrew Q Ta
- Lester and Sue Smith Breast Center, Baylor College of Medicine, Houston, TX 77030, USA
| | - Adeel A Faruki
- Lester and Sue Smith Breast Center, Baylor College of Medicine, Houston, TX 77030, USA
| | - Meng-Fen Wu
- Lester and Sue Smith Breast Center, Baylor College of Medicine, Houston, TX 77030, USA
| | - Susan G Hilsenbeck
- Lester and Sue Smith Breast Center, Baylor College of Medicine, Houston, TX 77030, USA. Department of Medicine, Baylor College of Medicine, Houston, TX 77030, USA
| | - Chad A Shaw
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Peng Yu
- Department of Electrical and Computer Engineering, TEES-AgriLife Center for Bioinformatics and Genomic Systems Engineering, Texas A&M University, College Station, TX 77843, USA
| | - Nicholas W Plummer
- Neurobiology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, USA
| | - Lutz Birnbaumer
- Neurobiology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, USA
| | - Michael T Lewis
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX 77030, USA. Lester and Sue Smith Breast Center, Baylor College of Medicine, Houston, TX 77030, USA. Department of Radiology, Baylor College of Medicine, Houston, TX 77030, USA.
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Platelet Gi protein Gαi2 is an essential mediator of thrombo-inflammatory organ damage in mice. Proc Natl Acad Sci U S A 2015; 112:6491-6. [PMID: 25944935 DOI: 10.1073/pnas.1505887112] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Platelets are crucial for hemostasis and thrombosis and exacerbate tissue injury following ischemia and reperfusion. Important regulators of platelet function are G proteins controlled by seven transmembrane receptors. The Gi protein Gα(i2) mediates platelet activation in vitro, but its in vivo role in hemostasis, arterial thrombosis, and postischemic infarct progression remains to be determined. Here we show that mice lacking Gα(i2) exhibit prolonged tail-bleeding times and markedly impaired thrombus formation and stability in different models of arterial thrombosis. We thus generated mice selectively lacking Gα(i2) in megakaryocytes and platelets (Gna(i2)(fl/fl)/PF4-Cre mice) and found bleeding defects comparable to those in global Gα(i2)-deficient mice. To examine the impact of platelet Gα(i2) in postischemic thrombo-inflammatory infarct progression, Gna(i2)(fl/fl)/PF4-Cre mice were subjected to experimental models of cerebral and myocardial ischemia/reperfusion injury. In the model of transient middle cerebral artery occlusion stroke Gna(i2)(fl/fl)/PF4-Cre mice developed significantly smaller brain infarcts and fewer neurological deficits than littermate controls. Following myocardial ischemia, Gna(i2)(fl/fl)/PF4-Cre mice showed dramatically reduced reperfusion injury which correlated with diminished formation of the ADP-dependent platelet neutrophil complex. In conclusion, our data provide definitive evidence that platelet Gα(i2) not only controls hemostatic and thrombotic responses but also is critical for the development of ischemia/reperfusion injury in vivo.
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28
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Wu D, Zhu X, Jimenez-Cowell K, Mold AJ, Sollecito CC, Lombana N, Jiao M, Wei Q. Identification of the GTPase-activating protein DEP domain containing 1B (DEPDC1B) as a transcriptional target of Pitx2. Exp Cell Res 2015; 333:80-92. [PMID: 25704760 PMCID: PMC4387072 DOI: 10.1016/j.yexcr.2015.02.008] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2014] [Revised: 01/17/2015] [Accepted: 02/10/2015] [Indexed: 10/25/2022]
Abstract
Pitx2 is a bicoid-related homeobox transcription factor implicated in regulating left-right patterning and organogenesis. However, only a limited number of Pitx2 downstream target genes have been identified and characterized. Here we demonstrate that Pitx2 is a transcriptional repressor of DEP domain containing 1B (DEPDC1B). The first intron of the human and mouse DEP domain containing 1B genes contains multiple consensus DNA-binding sites for Pitx2. Chromatin immunoprecipitation assays revealed that Pitx2, along with histone deacetylase 1, was recruited to the first intron of Depdc1b. In contrast, RNAi-mediated depletion of Pitx2 not only enhanced the acetylation of histone H4 in the first intron of Depdc1b, but also increased the protein level of Depdc1b. Luciferase reporter assays also showed that Pitx2 could repress the transcriptional activity mediated by the first intron of human DEPDC1B. The GAP domain of DEPDC1B interacted with nucleotide-bound forms of RAC1 in vitro. In addition, exogenous expression of DEPDC1B suppressed RAC1 activation and interfered with actin polymerization induced by the guanine nucleotide exchange factor TRIO. Moreover, DEPDC1B interacted with various signaling molecules such as U2af2, Erh, and Salm. We propose that Pitx2-mediated repression of Depdc1b expression contributes to the regulation of multiple molecular pathways, such as Rho GTPase signaling.
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Affiliation(s)
- Di Wu
- Department of Biological Sciences, Fordham University, Bronx, NY 10458, United States
| | - Xiaoxi Zhu
- Experimental and Clinical Research Center (ECRC), a Cooperation between Max Delbrück Center and Charité Universitätsmedizin Berlin, Campus Buch, Berlin, Germany
| | - Kevin Jimenez-Cowell
- Department of Biological Sciences, Fordham University, Bronx, NY 10458, United States
| | - Alexander J Mold
- Department of Biological Sciences, Fordham University, Bronx, NY 10458, United States
| | | | - Nicholas Lombana
- Department of Biological Sciences, Fordham University, Bronx, NY 10458, United States
| | - Meng Jiao
- Department of Biological Sciences, Fordham University, Bronx, NY 10458, United States
| | - Qize Wei
- Department of Biological Sciences, Fordham University, Bronx, NY 10458, United States.
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29
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Leiss V, Flockerzie K, Novakovic A, Rath M, Schönsiegel A, Birnbaumer L, Schürmann A, Harteneck C, Nürnberg B. Insulin secretion stimulated by L-arginine and its metabolite L-ornithine depends on Gα(i2). Am J Physiol Endocrinol Metab 2014; 307:E800-12. [PMID: 25205820 PMCID: PMC4216945 DOI: 10.1152/ajpendo.00337.2014] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Bordetella pertussis toxin (PTx), also known as islet-activating protein, induces insulin secretion by ADP-ribosylation of inhibitory G proteins. PTx-induced insulin secretion may result either from inactivation of Gα(o) proteins or from combined inactivation of Gα(o), Gα(i1), Gα(i2), and Gα(i3) isoforms. However, the specific role of Gα(i2) in pancreatic β-cells still remains unknown. In global (Gα(i2)(-/-)) and β-cell-specific (Gα(i2)(βcko)) gene-targeted Gα(i2) mouse models, we studied glucose homeostasis and islet functions. Insulin secretion experiments and intracellular Ca²⁺ measurements were used to characterize Gα(i2) function in vitro. Gα(i2)(-/-) and Gα(i2)(βcko) mice showed an unexpected metabolic phenotype, i.e., significantly lower plasma insulin levels upon intraperitoneal glucose challenge in Gα(i2)(-/-) and Gα(i2)(βcko) mice, whereas plasma glucose concentrations were unchanged in Gα(i2)(-/-) but significantly increased in Gα(i2)(βcko) mice. These findings indicate a novel albeit unexpected role for Gα(i2) in the expression, turnover, and/or release of insulin from islets. Detection of insulin secretion in isolated islets did not show differences in response to high (16 mM) glucose concentrations between control and β-cell-specific Gα(i2)-deficient mice. In contrast, the two- to threefold increase in insulin secretion evoked by L-arginine or L-ornithine (in the presence of 16 mM glucose) was significantly reduced in islets lacking Gα(i2). In accord with a reduced level of insulin secretion, intracellular calcium concentrations induced by the agonistic amino acid L-arginine did not reach control levels in β-cells. The presented analysis of gene-targeted mice provides novel insights in the role of β-cell Gα(i2) showing that amino acid-induced insulin-release depends on Gα(i2).
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MESH Headings
- Animals
- Arginine/metabolism
- Blood Glucose/analysis
- Calcium Signaling
- Crosses, Genetic
- Down-Regulation
- Fluorescent Antibody Technique
- GTP-Binding Protein alpha Subunit, Gi2/agonists
- GTP-Binding Protein alpha Subunit, Gi2/genetics
- GTP-Binding Protein alpha Subunit, Gi2/metabolism
- GTP-Binding Protein alpha Subunits, Gi-Go/agonists
- GTP-Binding Protein alpha Subunits, Gi-Go/genetics
- GTP-Binding Protein alpha Subunits, Gi-Go/metabolism
- Hyperglycemia/blood
- Hyperglycemia/metabolism
- Hyperglycemia/prevention & control
- Hypoglycemia/blood
- Hypoglycemia/metabolism
- Hypoglycemia/prevention & control
- Insulin/blood
- Insulin/metabolism
- Insulin Secretion
- Islets of Langerhans/cytology
- Islets of Langerhans/metabolism
- Mice, Inbred C57BL
- Mice, Knockout
- Mice, Transgenic
- Ornithine/blood
- Ornithine/metabolism
- Specific Pathogen-Free Organisms
- Tissue Culture Techniques
- Up-Regulation
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Affiliation(s)
- Veronika Leiss
- Department of Pharmacology and Experimental Therapy, Institute of Experimental and Clinical Pharmacology and Toxicology, Eberhard Karls University Hospitals and Clinics, and Interfaculty Center of Pharmacogenomics and Drug Research, University of Tübingen, Tübingen, Germany
| | - Katarina Flockerzie
- Department of Pharmacology and Experimental Therapy, Institute of Experimental and Clinical Pharmacology and Toxicology, Eberhard Karls University Hospitals and Clinics, and Interfaculty Center of Pharmacogenomics and Drug Research, University of Tübingen, Tübingen, Germany
| | - Ana Novakovic
- Department of Pharmacology and Experimental Therapy, Institute of Experimental and Clinical Pharmacology and Toxicology, Eberhard Karls University Hospitals and Clinics, and Interfaculty Center of Pharmacogenomics and Drug Research, University of Tübingen, Tübingen, Germany
| | - Michaela Rath
- Department of Experimental Diabetology, German Institute of Human Nutrition, Potsdam-Rehbrücke, Nuthetal, Germany
| | - Annika Schönsiegel
- Department of Pharmacology and Experimental Therapy, Institute of Experimental and Clinical Pharmacology and Toxicology, Eberhard Karls University Hospitals and Clinics, and Interfaculty Center of Pharmacogenomics and Drug Research, University of Tübingen, Tübingen, Germany
| | - Lutz Birnbaumer
- Laboratory of Neurobiology, National Institute of Environmental Health Sciences, National Institutes of Health/Department of Health and Human Services, Durham, North Carolina
| | - Annette Schürmann
- Department of Experimental Diabetology, German Institute of Human Nutrition, Potsdam-Rehbrücke, Nuthetal, Germany
| | - Christian Harteneck
- Department of Pharmacology and Experimental Therapy, Institute of Experimental and Clinical Pharmacology and Toxicology, Eberhard Karls University Hospitals and Clinics, and Interfaculty Center of Pharmacogenomics and Drug Research, University of Tübingen, Tübingen, Germany
| | - Bernd Nürnberg
- Department of Pharmacology and Experimental Therapy, Institute of Experimental and Clinical Pharmacology and Toxicology, Eberhard Karls University Hospitals and Clinics, and Interfaculty Center of Pharmacogenomics and Drug Research, University of Tübingen, Tübingen, Germany;
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30
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Rashid DJ, Chapman SC, Larsson HC, Organ CL, Bebin AG, Merzdorf CS, Bradley R, Horner JR. From dinosaurs to birds: a tail of evolution. EvoDevo 2014; 5:25. [PMID: 25621146 PMCID: PMC4304130 DOI: 10.1186/2041-9139-5-25] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2014] [Accepted: 07/10/2014] [Indexed: 01/09/2023] Open
Abstract
A particularly critical event in avian evolution was the transition from long- to short-tailed birds. Primitive bird tails underwent significant alteration, most notably reduction of the number of caudal vertebrae and fusion of the distal caudal vertebrae into an ossified pygostyle. These changes, among others, occurred over a very short evolutionary interval, which brings into focus the underlying mechanisms behind those changes. Despite the wealth of studies delving into avian evolution, virtually nothing is understood about the genetic and developmental events responsible for the emergence of short, fused tails. In this review, we summarize the current understanding of the signaling pathways and morphological events that contribute to tail extension and termination and examine how mutations affecting the genes that control these pathways might influence the evolution of the avian tail. To generate a list of candidate genes that may have been modulated in the transition to short-tailed birds, we analyzed a comprehensive set of mouse mutants. Interestingly, a prevalent pleiotropic effect of mutations that cause fused caudal vertebral bodies (as in the pygostyles of birds) is tail truncation. We identified 23 mutations in this class, and these were primarily restricted to genes involved in axial extension. At least half of the mutations that cause short, fused tails lie in the Notch/Wnt pathway of somite boundary formation or differentiation, leading to changes in somite number or size. Several of the mutations also cause additional bone fusions in the trunk skeleton, reminiscent of those observed in primitive and modern birds. All of our findings were correlated to the fossil record. An open question is whether the relatively sudden appearance of short-tailed birds in the fossil record could be accounted for, at least in part, by the pleiotropic effects generated by a relatively small number of mutational events.
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Affiliation(s)
- Dana J Rashid
- Museum of the Rockies, Montana State University, 600 West Kagy Blvd, Bozeman, MT 59717, USA
| | - Susan C Chapman
- Department of Biological Sciences, Clemson University, 340 Long Hall, Clemson, SC 29634, USA
| | - Hans Ce Larsson
- Redpath Museum, McGill University, 859 Sherbrooke Street W., Montreal, Quebec H3A 0C4, Canada
| | - Chris L Organ
- Museum of the Rockies, Montana State University, 600 West Kagy Blvd, Bozeman, MT 59717, USA ; Department of Earth Sciences, Montana State University, 226 Traphagen Hall, Bozeman, MT 59717, USA
| | - Anne-Gaelle Bebin
- Museum of the Rockies, Montana State University, 600 West Kagy Blvd, Bozeman, MT 59717, USA ; Current address: Vaccine and Gene Therapy FL, 9801 Discovery Way, Port Lucie, FL 34987, USA
| | - Christa S Merzdorf
- Department of Cell Biology & Neuroscience, Montana State University, 513 Leon Johnson Hall, Bozeman, MT 59717, USA
| | - Roger Bradley
- Department of Cell Biology & Neuroscience, Montana State University, 513 Leon Johnson Hall, Bozeman, MT 59717, USA
| | - John R Horner
- Museum of the Rockies, Montana State University, 600 West Kagy Blvd, Bozeman, MT 59717, USA
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31
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Novel variants in GNAI3 associated with auriculocondylar syndrome strengthen a common dominant negative effect. Eur J Hum Genet 2014; 23:481-5. [PMID: 25026904 DOI: 10.1038/ejhg.2014.132] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2014] [Revised: 06/03/2014] [Accepted: 06/06/2014] [Indexed: 12/21/2022] Open
Abstract
Auriculocondylar syndrome is a rare craniofacial disorder comprising core features of micrognathia, condyle dysplasia and question mark ear. Causative variants have been identified in PLCB4, GNAI3 and EDN1, which are predicted to function within the EDN1-EDNRA pathway during early pharyngeal arch patterning. To date, two GNAI3 variants in three families have been reported. Here we report three novel GNAI3 variants, one segregating with affected members in a family previously linked to 1p21.1-q23.3 and two de novo variants in simplex cases. Two variants occur in known functional motifs, the G1 and G4 boxes, and the third variant is one amino acid outside of the G1 box. Structural modeling shows that all five altered GNAI3 residues identified to date cluster in a region involved in GDP/GTP binding. We hypothesize that all GNAI3 variants lead to dominant negative effects.
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32
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Köhler D, Devanathan V, Bernardo de Oliveira Franz C, Eldh T, Novakovic A, Roth JM, Granja T, Birnbaumer L, Rosenberger P, Beer-Hammer S, Nürnberg B. Gαi2- and Gαi3-deficient mice display opposite severity of myocardial ischemia reperfusion injury. PLoS One 2014; 9:e98325. [PMID: 24858945 PMCID: PMC4032280 DOI: 10.1371/journal.pone.0098325] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2014] [Accepted: 04/30/2014] [Indexed: 12/19/2022] Open
Abstract
G-protein-coupled receptors (GPCRs) are the most abundant receptors in the heart and therefore are common targets for cardiovascular therapeutics. The activated GPCRs transduce their signals via heterotrimeric G-proteins. The four major families of G-proteins identified so far are specified through their α-subunit: Gαi, Gαs, Gαq and G12/13. Gαi-proteins have been reported to protect hearts from ischemia reperfusion injury. However, determining the individual impact of Gαi2 or Gαi3 on myocardial ischemia injury has not been clarified yet. Here, we first investigated expression of Gαi2 and Gαi3 on transcriptional level by quantitative PCR and on protein level by immunoblot analysis as well as by immunofluorescence in cardiac tissues of wild-type, Gαi2-, and Gαi3-deficient mice. Gαi2 was expressed at higher levels than Gαi3 in murine hearts, and irrespective of the isoform being knocked out we observed an up regulation of the remaining Gαi-protein. Myocardial ischemia promptly regulated cardiac mRNA and with a slight delay protein levels of both Gαi2 and Gαi3, indicating important roles for both Gαi isoforms. Furthermore, ischemia reperfusion injury in Gαi2- and Gαi3-deficient mice exhibited opposite outcomes. Whereas the absence of Gαi2 significantly increased the infarct size in the heart, the absence of Gαi3 or the concomitant upregulation of Gαi2 dramatically reduced cardiac infarction. In conclusion, we demonstrate for the first time that the genetic ablation of Gαi proteins has protective or deleterious effects on cardiac ischemia reperfusion injury depending on the isoform being absent.
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Affiliation(s)
- David Köhler
- Department of Anesthesiology and Intensive Care Medicine, Institute of Experimental and Clinical Pharmacology and Toxicology, Eberhard Karls University Hospitals and Clinics, and Interfaculty Center of Pharmacogenomics and Drug Research, Tuebingen, Germany
| | - Vasudharani Devanathan
- Department of Pharmacology and Experimental Therapy, Institute of Experimental and Clinical Pharmacology and Toxicology, Eberhard Karls University Hospitals and Clinics, and Interfaculty Center of Pharmacogenomics and Drug Research, Tuebingen, Germany
| | - Claudia Bernardo de Oliveira Franz
- Department of Anesthesiology and Intensive Care Medicine, Institute of Experimental and Clinical Pharmacology and Toxicology, Eberhard Karls University Hospitals and Clinics, and Interfaculty Center of Pharmacogenomics and Drug Research, Tuebingen, Germany
| | - Therese Eldh
- Department of Pharmacology and Experimental Therapy, Institute of Experimental and Clinical Pharmacology and Toxicology, Eberhard Karls University Hospitals and Clinics, and Interfaculty Center of Pharmacogenomics and Drug Research, Tuebingen, Germany
| | - Ana Novakovic
- Department of Pharmacology and Experimental Therapy, Institute of Experimental and Clinical Pharmacology and Toxicology, Eberhard Karls University Hospitals and Clinics, and Interfaculty Center of Pharmacogenomics and Drug Research, Tuebingen, Germany
| | - Judith M. Roth
- Department of Anesthesiology and Intensive Care Medicine, Institute of Experimental and Clinical Pharmacology and Toxicology, Eberhard Karls University Hospitals and Clinics, and Interfaculty Center of Pharmacogenomics and Drug Research, Tuebingen, Germany
| | - Tiago Granja
- Department of Anesthesiology and Intensive Care Medicine, Institute of Experimental and Clinical Pharmacology and Toxicology, Eberhard Karls University Hospitals and Clinics, and Interfaculty Center of Pharmacogenomics and Drug Research, Tuebingen, Germany
| | - Lutz Birnbaumer
- Laboratory of Neurobiology, Division of Intramural Research, National Institute of Environmental Health Sciences, National Institutes of Health, Department of Health and Human Services, Research Triangle Park, North Carolina, United States of America
| | - Peter Rosenberger
- Department of Anesthesiology and Intensive Care Medicine, Institute of Experimental and Clinical Pharmacology and Toxicology, Eberhard Karls University Hospitals and Clinics, and Interfaculty Center of Pharmacogenomics and Drug Research, Tuebingen, Germany
| | - Sandra Beer-Hammer
- Department of Pharmacology and Experimental Therapy, Institute of Experimental and Clinical Pharmacology and Toxicology, Eberhard Karls University Hospitals and Clinics, and Interfaculty Center of Pharmacogenomics and Drug Research, Tuebingen, Germany
- * E-mail: (SBH); (BN)
| | - Bernd Nürnberg
- Department of Pharmacology and Experimental Therapy, Institute of Experimental and Clinical Pharmacology and Toxicology, Eberhard Karls University Hospitals and Clinics, and Interfaculty Center of Pharmacogenomics and Drug Research, Tuebingen, Germany
- * E-mail: (SBH); (BN)
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33
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Disruption of G-protein γ5 subtype causes embryonic lethality in mice. PLoS One 2014; 9:e90970. [PMID: 24599258 PMCID: PMC3944967 DOI: 10.1371/journal.pone.0090970] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2013] [Accepted: 02/06/2014] [Indexed: 12/01/2022] Open
Abstract
Heterotrimeric G-proteins modulate many processes essential for embryonic development including cellular proliferation, migration, differentiation, and survival. Although most research has focused on identifying the roles of the various αsubtypes, there is growing recognition that similarly divergent βγ dimers also regulate these processes. In this paper, we show that targeted disruption of the mouse Gng5 gene encoding the γ5 subtype produces embryonic lethality associated with severe head and heart defects. Collectively, these results add to a growing body of data that identify critical roles for the γ subunits in directing the assembly of functionally distinct G-αβγ trimers that are responsible for regulating diverse biological processes. Specifically, the finding that loss of the G-γ5 subtype is associated with a reduced number of cardiac precursor cells not only provides a causal basis for the mouse phenotype but also raises the possibility that G-βγ5 dependent signaling contributes to the pathogenesis of human congenital heart problems.
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Gαi2 signaling is required for skeletal muscle growth, regeneration, and satellite cell proliferation and differentiation. Mol Cell Biol 2013; 34:619-30. [PMID: 24298018 DOI: 10.1128/mcb.00957-13] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
We have previously shown that activation of Gαi2, an α subunit of the heterotrimeric G protein complex, induces skeletal muscle hypertrophy and myoblast differentiation. To determine whether Gαi2 is required for skeletal muscle growth or regeneration, Gαi2-null mice were analyzed. Gαi2 knockout mice display decreased lean body mass, reduced muscle size, and impaired skeletal muscle regeneration after cardiotoxin-induced injury. Short hairpin RNA (shRNA)-mediated knockdown of Gαi2 in satellite cells (SCs) leads to defective satellite cell proliferation, fusion, and differentiation ex vivo. The impaired differentiation is consistent with the observation that the myogenic regulatory factors MyoD and Myf5 are downregulated upon knockdown of Gαi2. Interestingly, the expression of microRNA 1 (miR-1), miR-27b, and miR-206, three microRNAs that have been shown to regulate SC proliferation and differentiation, is increased by a constitutively active mutant of Gαi2 [Gαi2(Q205L)] and counterregulated by Gαi2 knockdown. As for the mechanism, this study demonstrates that Gαi2(Q205L) regulates satellite cell differentiation into myotubes in a protein kinase C (PKC)- and histone deacetylase (HDAC)-dependent manner.
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Clouthier DE, Passos-Bueno MR, Tavares ALP, Lyonnet S, Amiel J, Gordon CT. Understanding the basis of auriculocondylar syndrome: Insights from human, mouse and zebrafish genetic studies. AMERICAN JOURNAL OF MEDICAL GENETICS PART C-SEMINARS IN MEDICAL GENETICS 2013; 163C:306-17. [PMID: 24123988 DOI: 10.1002/ajmg.c.31376] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Among human birth defect syndromes, malformations affecting the face are perhaps the most striking due to cultural and psychological expectations of facial shape. One such syndrome is auriculocondylar syndrome (ACS), in which patients present with defects in ear and mandible development. Affected structures arise from cranial neural crest cells, a population of cells in the embryo that reside in the pharyngeal arches and give rise to most of the bone, cartilage and connective tissue of the face. Recent studies have found that most cases of ACS arise from defects in signaling molecules associated with the endothelin signaling pathway. Disruption of this signaling pathway in both mouse and zebrafish results in loss of identity of neural crest cells of the mandibular portion of the first pharyngeal arch and the subsequent repatterning of these cells, leading to homeosis of lower jaw structures into more maxillary-like structures. These findings illustrate the importance of endothelin signaling in normal human craniofacial development and illustrate how clinical and basic science approaches can coalesce to improve our understanding of the genetic basis of human birth defect syndromes. Further, understanding the genetic basis for ACS that lies outside of known endothelin signaling components may help elucidate unknown aspects critical to the establishment of neural crest cell patterning during facial morphogenesis.
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Hwang IY, Park C, Luong T, Harrison KA, Birnbaumer L, Kehrl JH. The loss of Gnai2 and Gnai3 in B cells eliminates B lymphocyte compartments and leads to a hyper-IgM like syndrome. PLoS One 2013; 8:e72596. [PMID: 23977324 PMCID: PMC3747273 DOI: 10.1371/journal.pone.0072596] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2013] [Accepted: 07/18/2013] [Indexed: 11/22/2022] Open
Abstract
B lymphocytes are compartmentalized within lymphoid organs. The organization of these compartments depends upon signaling initiated by G-protein linked chemoattractant receptors. To address the importance of the G-proteins Gαi2 and Gαi3 in chemoattractant signaling we created mice lacking both proteins in their B lymphocytes. While bone marrow B cell development and egress is grossly intact; mucosal sites, splenic marginal zones, and lymph nodes essentially lack B cells. There is a partial block in splenic follicular B cell development and a 50-60% reduction in splenic B cells, yet normal numbers of splenic T cells. The absence of Gαi2 and Gαi3 in B cells profoundly disturbs the architecture of lymphoid organs with loss of B cell compartments in the spleen, thymus, lymph nodes, and gastrointestinal tract. This results in a severe disruption of B cell function and a hyper-IgM like syndrome. Beyond the pro-B cell stage, B cells are refractory to chemokine stimulation, and splenic B cells are poorly responsive to antigen receptor engagement. Gαi2 and Gαi3 are therefore critical for B cell chemoattractant receptor signaling and for normal B cell function. These mice provide a worst case scenario of the consequences of losing chemoattractant receptor signaling in B cells.
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Affiliation(s)
- Il-Young Hwang
- B Cell Molecular Immunology Section, Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Chung Park
- B Cell Molecular Immunology Section, Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Thuyvi Luong
- B Cell Molecular Immunology Section, Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Kathleen A. Harrison
- B Cell Molecular Immunology Section, Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Lutz Birnbaumer
- Laboratory of Neurobiology, National Institute of Environmental Health Sciences, National Institutes of Health/Department of Health and Human Services, Durham, North Carolina, United States of America
| | - John H. Kehrl
- B Cell Molecular Immunology Section, Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
- * E-mail:
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